Add command_prelude module (#12291)

# Description
When implementing a `Command`, one must also import all the types
present in the function signatures for `Command`. This makes it so that
we often import the same set of types in each command implementation
file. E.g., something like this:
```rust
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
    record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData,
    ShellError, Signature, Span, Type, Value,
};
```

This PR adds the `nu_engine::command_prelude` module which contains the
necessary and commonly used types to implement a `Command`:
```rust
// command_prelude.rs
pub use crate::CallExt;
pub use nu_protocol::{
    ast::{Call, CellPath},
    engine::{Command, EngineState, Stack},
    record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, IntoSpanned,
    PipelineData, Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
};
```

This should reduce the boilerplate needed to implement a command and
also gives us a place to track the breadth of the `Command` API. I tried
to be conservative with what went into the prelude modules, since it
might be hard/annoying to remove items from the prelude in the future.
Let me know if something should be included or excluded.

crates/nu-command/src/conversions/fill.rs

@@ -1,10 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+
 use print_positions::print_positions;
 
 #[derive(Clone)]

crates/nu-command/src/conversions/into/binary.rs

@@ -1,11 +1,5 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 pub struct Arguments {
     cell_paths: Option<Vec<CellPath>>,

crates/nu-command/src/conversions/into/bool.rs

@@ -1,10 +1,5 @@
 use nu_cmd_base::input_handler::{operate, CellPathOnlyArgs};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct SubCommand;

crates/nu-command/src/conversions/into/cell_path.rs

@@ -1,9 +1,5 @@
-use nu_protocol::{
-    ast::{Call, CellPath, PathMember},
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, Record, ShellError, Signature, Span, Type,
-    Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::ast::{CellPath, PathMember};
 
 #[derive(Clone)]
 pub struct IntoCellPath;

crates/nu-command/src/conversions/into/command.rs

@@ -1,9 +1,4 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::{command_prelude::*, get_full_help};
 
 #[derive(Clone)]
 pub struct Into;

crates/nu-command/src/conversions/into/datetime.rs

@@ -1,15 +1,8 @@
 use crate::{generate_strftime_list, parse_date_from_string};
-use chrono::NaiveTime;
-use chrono::{DateTime, FixedOffset, Local, TimeZone, Utc};
+use chrono::{DateTime, FixedOffset, Local, NaiveTime, TimeZone, Utc};
 use human_date_parser::{from_human_time, ParseResult};
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span,
-    Spanned, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 struct Arguments {
     zone_options: Option<Spanned<Zone>>,

crates/nu-command/src/conversions/into/duration.rs

@@ -1,10 +1,8 @@
-use nu_engine::CallExt;
+use nu_engine::command_prelude::*;
 use nu_parser::{parse_unit_value, DURATION_UNIT_GROUPS};
 use nu_protocol::{
-    ast::{Call, CellPath, Expr},
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Unit,
-    Value,
+    ast::{CellPath, Expr},
+    Unit,
 };
 
 const NS_PER_SEC: i64 = 1_000_000_000;

crates/nu-command/src/conversions/into/filesize.rs

@@ -1,10 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CellPathOnlyArgs};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+
 use nu_utils::get_system_locale;
 
 #[derive(Clone)]

crates/nu-command/src/conversions/into/float.rs

@@ -1,10 +1,5 @@
 use nu_cmd_base::input_handler::{operate, CellPathOnlyArgs};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    record, Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct SubCommand;

crates/nu-command/src/conversions/into/glob.rs

@@ -1,11 +1,5 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
-    Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 struct Arguments {
     cell_paths: Option<Vec<CellPath>>,

crates/nu-command/src/conversions/into/int.rs

@@ -1,11 +1,7 @@
 use chrono::{FixedOffset, TimeZone};
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+
 use nu_utils::get_system_locale;
 
 struct Arguments {

crates/nu-command/src/conversions/into/record.rs

@@ -1,10 +1,6 @@
 use chrono::{DateTime, Datelike, FixedOffset, Timelike};
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    format_duration_as_timeperiod, record, Category, Example, IntoPipelineData, PipelineData,
-    Record, ShellError, Signature, Span, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::format_duration_as_timeperiod;
 
 #[derive(Clone)]
 pub struct SubCommand;

crates/nu-command/src/conversions/into/string.rs

@@ -1,11 +1,6 @@
 use nu_cmd_base::input_handler::{operate, CmdArgument};
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::{Call, CellPath},
-    engine::{Command, EngineState, Stack},
-    into_code, Category, Config, Example, IntoPipelineData, PipelineData, ShellError, Signature,
-    Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::{into_code, Config};
 use nu_utils::get_system_locale;
 use num_format::ToFormattedString;
 

crates/nu-command/src/conversions/into/value.rs

@@ -1,11 +1,6 @@
 use crate::parse_date_from_string;
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoInterruptiblePipelineData, PipelineData, PipelineIterator, ShellError,
-    Signature, Span, SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::PipelineIterator;
 use once_cell::sync::Lazy;
 use regex::{Regex, RegexBuilder};
 use std::collections::HashSet;