A fill command to replace str lpad and str rpad (#7846)

# Description

The point of this command is to allow you to be able to format ints,
floats, filesizes, and strings with an alignment, padding, and a fill
character, as strings. It's meant to take the place of `str lpad` and
`str rpad`.

```
> help fill
Fill and Align

Search terms: display, render, format, pad, align

Usage:
  > fill {flags}

Flags:
  -h, --help - Display the help message for this command
  -w, --width <Int> - The width of the output. Defaults to 1
  -a, --alignment <String> - The alignment of the output. Defaults to Left (Left(l), Right(r), Center(c/m), MiddleRight(cr/mr))
  -c, --character <String> - The character to fill with. Defaults to ' ' (space)

Signatures:
  <number> | fill -> <string>
  <string> | fill -> <string>

Examples:
  Fill a string on the left side to a width of 15 with the character '─'
  > 'nushell' | fill -a l -c '─' -w 15

  Fill a string on the right side to a width of 15 with the character '─'
  > 'nushell' | fill -a r -c '─' -w 15

  Fill a string on both sides to a width of 15 with the character '─'
  > 'nushell' | fill -a m -c '─' -w 15

  Fill a number on the left side to a width of 5 with the character '0'
  > 1 | fill --alignment right --character 0 --width 5

  Fill a filesize on the left side to a width of 5 with the character '0'
  > 1kib | fill --alignment middle --character 0 --width 10
```

![image](https://user-images.githubusercontent.com/343840/214133752-6fc93fa7-4003-4eb4-96ed-cd967312e244.png)

# User-Facing Changes

Deprecated `str lpad` and `str rpad`.

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/src/deprecated/deprecated_commands.rs

@@ -20,5 +20,7 @@ pub fn deprecated_commands() -> HashMap<String, String> {
         ),
         ("fetch".to_string(), "http get".to_string()),
         ("post".to_string(), "http post".to_string()),
+        ("str lpad".to_string(), "fill".to_string()),
+        ("str rpad".to_string(), "fill".to_string()),
     ])
 }

crates/nu-command/src/deprecated/lpad.rs

@@ -0,0 +1,35 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::Category;
+use nu_protocol::{PipelineData, ShellError, Signature};
+
+#[derive(Clone)]
+pub struct LPadDeprecated;
+
+impl Command for LPadDeprecated {
+    fn name(&self) -> &str {
+        "str lpad"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name()).category(Category::Deprecated)
+    }
+
+    fn usage(&self) -> &str {
+        "Deprecated command"
+    }
+
+    fn run(
+        &self,
+        _: &EngineState,
+        _: &mut Stack,
+        call: &Call,
+        _: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        Err(nu_protocol::ShellError::DeprecatedCommand(
+            self.name().to_string(),
+            "fill".to_owned(),
+            call.head,
+        ))
+    }
+}

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

@@ -1,6 +1,8 @@
 mod deprecated_commands;
 mod hash_base64;
+mod lpad;
 mod math_eval;
+mod rpad;
 mod source;
 mod str_datetime;
 mod str_decimal;
@@ -9,7 +11,9 @@ mod str_int;
 
 pub use deprecated_commands::*;
 pub use hash_base64::HashBase64;
+pub use lpad::LPadDeprecated;
 pub use math_eval::SubCommand as MathEvalDeprecated;
+pub use rpad::RPadDeprecated;
 pub use source::Source;
 pub use str_datetime::StrDatetimeDeprecated;
 pub use str_decimal::StrDecimalDeprecated;

crates/nu-command/src/deprecated/rpad.rs

@@ -0,0 +1,35 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::Category;
+use nu_protocol::{PipelineData, ShellError, Signature};
+
+#[derive(Clone)]
+pub struct RPadDeprecated;
+
+impl Command for RPadDeprecated {
+    fn name(&self) -> &str {
+        "str rpad"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name()).category(Category::Deprecated)
+    }
+
+    fn usage(&self) -> &str {
+        "Deprecated command"
+    }
+
+    fn run(
+        &self,
+        _: &EngineState,
+        _: &mut Stack,
+        call: &Call,
+        _: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        Err(nu_protocol::ShellError::DeprecatedCommand(
+            self.name().to_string(),
+            "fill".to_owned(),
+            call.head,
+        ))
+    }
+}