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-protocol/src/value/from_value.rs

@@ -1,10 +1,10 @@
-use std::path::PathBuf;
-
-use super::NuGlob;
-use crate::ast::{CellPath, PathMember};
-use crate::engine::{Block, Closure};
-use crate::{Range, Record, ShellError, Spanned, Value};
+use crate::{
+    ast::{CellPath, PathMember},
+    engine::{Block, Closure},
+    NuGlob, Range, Record, ShellError, Spanned, Value,
+};
 use chrono::{DateTime, FixedOffset};
+use std::path::PathBuf;
 
 pub trait FromValue: Sized {
     fn from_value(v: Value) -> Result<Self, ShellError>;

crates/nu-protocol/src/value/mod.rs

@@ -17,23 +17,26 @@ pub use lazy_record::LazyRecord;
 pub use range::*;
 pub use record::Record;
 
-use crate::ast::{Bits, Boolean, CellPath, Comparison, Math, Operator, PathMember, RangeInclusion};
-use crate::engine::{Closure, EngineState};
-use crate::{did_you_mean, BlockId, Config, ShellError, Span, Type};
-
+use crate::{
+    ast::{Bits, Boolean, CellPath, Comparison, Math, Operator, PathMember, RangeInclusion},
+    did_you_mean,
+    engine::{Closure, EngineState},
+    BlockId, Config, ShellError, Span, Type,
+};
 use chrono::{DateTime, Datelike, FixedOffset, Locale, TimeZone};
 use chrono_humanize::HumanTime;
 use fancy_regex::Regex;
-use nu_utils::locale::LOCALE_OVERRIDE_ENV_VAR;
-use nu_utils::{contains_emoji, locale::get_system_locale_string, IgnoreCaseExt};
+use nu_utils::{
+    contains_emoji,
+    locale::{get_system_locale_string, LOCALE_OVERRIDE_ENV_VAR},
+    IgnoreCaseExt,
+};
 use serde::{Deserialize, Serialize};
-use std::fmt::Write;
-
 use std::{
     borrow::Cow,
-    fmt::Display,
+    cmp::Ordering,
+    fmt::{Debug, Display, Write},
     path::PathBuf,
-    {cmp::Ordering, fmt::Debug},
 };
 
 /// Core structured values that pass through the pipeline in Nushell.