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/debug/ast.rs

@@ -1,11 +1,6 @@
-use nu_engine::CallExt;
+use nu_engine::command_prelude::*;
 use nu_parser::parse;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack, StateWorkingSet},
-    record, Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span,
-    Spanned, SyntaxShape, Type, Value,
-};
+use nu_protocol::engine::StateWorkingSet;
 
 #[derive(Clone)]
 pub struct Ast;

crates/nu-command/src/debug/debug_.rs

@@ -1,7 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Span, Type, Value};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct Debug;

crates/nu-command/src/debug/explain.rs

@@ -1,10 +1,7 @@
-use nu_engine::{get_eval_expression, CallExt};
-use nu_protocol::ast::{Argument, Block, Call, Expr, Expression};
-
-use nu_protocol::engine::{Closure, Command, EngineState, Stack};
+use nu_engine::{command_prelude::*, get_eval_expression};
 use nu_protocol::{
-    record, Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature,
-    Span, SyntaxShape, Type, Value,
+    ast::{Argument, Block, Expr, Expression},
+    engine::Closure,
 };
 
 #[derive(Clone)]

crates/nu-command/src/debug/info.rs

@@ -1,10 +1,7 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, IntoPipelineData, LazyRecord, PipelineData, Record, ShellError,
-    Signature, Span, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::LazyRecord;
 use sysinfo::{MemoryRefreshKind, Pid, ProcessRefreshKind, RefreshKind, System};
+
 const ENV_PATH_SEPARATOR_CHAR: char = {
     #[cfg(target_family = "windows")]
     {

crates/nu-command/src/debug/inspect.rs

@@ -1,9 +1,5 @@
 use super::inspect_table;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type,
-};
+use nu_engine::command_prelude::*;
 use terminal_size::{terminal_size, Height, Width};
 
 #[derive(Clone)]

crates/nu-command/src/debug/inspect_table.rs

@@ -1,3 +1,6 @@
+use crate::debug::inspect_table::{
+    global_horizontal_char::SetHorizontalChar, set_widths::SetWidths,
+};
 use nu_protocol::Value;
 use nu_table::{string_width, string_wrap};
 use tabled::{
@@ -6,10 +9,6 @@ use tabled::{
     Table,
 };
 
-use crate::debug::inspect_table::{
-    global_horizontal_char::SetHorizontalChar, set_widths::SetWidths,
-};
-
 pub fn build_table(value: Value, description: String, termsize: usize) -> String {
     let (head, mut data) = util::collect_input(value);
     let count_columns = head.len();

crates/nu-command/src/debug/metadata.rs

@@ -1,9 +1,7 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::{Call, Expr, Expression};
-use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_engine::command_prelude::*;
 use nu_protocol::{
-    record, Category, DataSource, Example, IntoPipelineData, PipelineData, PipelineMetadata,
-    Record, ShellError, Signature, Span, SyntaxShape, Type, Value,
+    ast::{Expr, Expression},
+    DataSource, PipelineMetadata,
 };
 
 #[derive(Clone)]

crates/nu-command/src/debug/profile.rs

@@ -1,9 +1,7 @@
-use nu_engine::{eval_block_with_early_return, CallExt};
-use nu_protocol::ast::Call;
-use nu_protocol::debugger::{Profiler, WithDebug};
-use nu_protocol::engine::{Closure, Command, EngineState, Stack};
+use nu_engine::{command_prelude::*, eval_block_with_early_return};
 use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Type,
+    debugger::{Profiler, WithDebug},
+    engine::Closure,
 };
 
 #[derive(Clone)]

crates/nu-command/src/debug/timeit.rs

@@ -1,11 +1,4 @@
-use nu_engine::{get_eval_block, get_eval_expression_with_input};
-
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::{command_prelude::*, get_eval_block, get_eval_expression_with_input};
 use std::time::Instant;
 
 #[derive(Clone)]

crates/nu-command/src/debug/view.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 View;

crates/nu-command/src/debug/view_files.rs

@@ -1,8 +1,4 @@
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    record, Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ViewFiles;

crates/nu-command/src/debug/view_source.rs

@@ -1,10 +1,5 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, SyntaxShape, Type,
-    Value,
-};
+use nu_engine::command_prelude::*;
+
 use std::fmt::Write;
 
 #[derive(Clone)]

crates/nu-command/src/debug/view_span.rs

@@ -1,10 +1,4 @@
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{
-    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
 
 #[derive(Clone)]
 pub struct ViewSpan;