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/path/basename.rs

@@ -1,13 +1,7 @@
-use std::path::Path;
-
 use super::PathSubcommandArguments;
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
-};
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::Path;
 
 struct Arguments {
     replace: Option<Spanned<String>>,

crates/nu-command/src/path/dirname.rs

@@ -1,14 +1,7 @@
-use std::path::Path;
-
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::Path;
 
 struct Arguments {
     replace: Option<Spanned<String>>,

crates/nu-command/src/path/exists.rs

@@ -1,14 +1,8 @@
-use std::path::{Path, PathBuf};
-
-use nu_engine::{current_dir, current_dir_const, CallExt};
-use nu_path::expand_path_with;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::{command_prelude::*, current_dir, current_dir_const};
+use nu_path::expand_path_with;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::{Path, PathBuf};
 
 struct Arguments {
     pwd: PathBuf,

crates/nu-command/src/path/expand.rs

@@ -1,15 +1,11 @@
-use std::path::Path;
-
-use nu_engine::env::{current_dir_str, current_dir_str_const};
-use nu_engine::CallExt;
-use nu_path::{canonicalize_with, expand_path_with};
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::{
+    command_prelude::*,
+    env::{current_dir_str, current_dir_str_const},
+};
+use nu_path::{canonicalize_with, expand_path_with};
+use nu_protocol::engine::StateWorkingSet;
+use std::path::Path;
 
 struct Arguments {
     strict: bool,

crates/nu-command/src/path/join.rs

@@ -1,14 +1,7 @@
-use std::path::{Path, PathBuf};
-
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, Record, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::{Path, PathBuf};
 
 struct Arguments {
     append: Vec<Spanned<String>>,

crates/nu-command/src/path/mod.rs

@@ -9,8 +9,6 @@ mod relative_to;
 mod split;
 mod r#type;
 
-use std::path::Path as StdPath;
-
 pub use basename::SubCommand as PathBasename;
 pub use dirname::SubCommand as PathDirname;
 pub use exists::SubCommand as PathExists;
@@ -23,6 +21,7 @@ pub use relative_to::SubCommand as PathRelativeTo;
 pub use split::SubCommand as PathSplit;
 
 use nu_protocol::{ShellError, Span, Value};
+use std::path::Path as StdPath;
 
 #[cfg(windows)]
 const ALLOWED_COLUMNS: [&str; 4] = ["prefix", "parent", "stem", "extension"];

crates/nu-command/src/path/parse.rs

@@ -1,14 +1,7 @@
-use std::path::Path;
-
-use nu_engine::CallExt;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, Record, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::Path;
 
 struct Arguments {
     extension: Option<Spanned<String>>,
@@ -97,8 +90,6 @@ On Windows, an extra 'prefix' column is added."#
 
     #[cfg(windows)]
     fn examples(&self) -> Vec<Example> {
-        use nu_protocol::record;
-
         vec![
             Example {
                 description: "Parse a single path",
@@ -148,8 +139,6 @@ On Windows, an extra 'prefix' column is added."#
 
     #[cfg(not(windows))]
     fn examples(&self) -> Vec<Example> {
-        use nu_protocol::record;
-
         vec![
             Example {
                 description: "Parse a path",

crates/nu-command/src/path/path_.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 PathCommand;

crates/nu-command/src/path/relative_to.rs

@@ -1,15 +1,8 @@
-use std::path::Path;
-
-use nu_engine::CallExt;
-use nu_path::expand_to_real_path;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Spanned,
-    SyntaxShape, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::command_prelude::*;
+use nu_path::expand_to_real_path;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::Path;
 
 struct Arguments {
     path: Spanned<String>,

crates/nu-command/src/path/split.rs

@@ -1,12 +1,7 @@
-use std::path::{Component, Path};
-
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::command_prelude::*;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::{Component, Path};
 
 struct Arguments;
 

crates/nu-command/src/path/type.rs

@@ -1,13 +1,8 @@
-use std::path::Path;
-
-use nu_path::expand_tilde;
-use nu_protocol::ast::Call;
-use nu_protocol::engine::{EngineState, Stack, StateWorkingSet};
-use nu_protocol::{
-    engine::Command, Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
-};
-
 use super::PathSubcommandArguments;
+use nu_engine::command_prelude::*;
+use nu_path::expand_tilde;
+use nu_protocol::engine::StateWorkingSet;
+use std::path::Path;
 
 struct Arguments;