New commands: break, continue, return, and loop (#7230)

# Description

This adds `break`, `continue`, `return`, and `loop`.

* `break` - breaks out a loop
* `continue` - continues a loop at the next iteration
* `return` - early return from a function call
* `loop` - loop forever (until the loop hits a break)

Examples:
```
for i in 1..10 {
    if $i == 5 {
       continue
    } 
    print $i
}
```

```
for i in 1..10 {
    if $i == 5 {
        break
    } 
    print $i
}
```

```
def foo [x] {
    if true {
        return 2
    }
    $x
}
foo 100
```

```
loop { print "hello, forever" }
```

```
[1, 2, 3, 4, 5] | each {|x| 
    if $x > 3 { break }
    $x
}
```

# User-Facing Changes

Adds the above commands.

# 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-cli/src/repl.rs

@@ -10,7 +10,7 @@ use lazy_static::lazy_static;
 use log::{info, trace, warn};
 use miette::{IntoDiagnostic, Result};
 use nu_color_config::get_color_config;
-use nu_engine::{convert_env_values, eval_block};
+use nu_engine::{convert_env_values, eval_block, eval_block_with_early_return};
 use nu_parser::{lex, parse, trim_quotes_str};
 use nu_protocol::{
     ast::PathMember,
@@ -962,7 +962,8 @@ pub fn run_hook_block(
         }
     }
 
-    match eval_block(engine_state, &mut callee_stack, block, input, false, false) {
+    match eval_block_with_early_return(engine_state, &mut callee_stack, block, input, false, false)
+    {
         Ok(pipeline_data) => match pipeline_data.into_value(span) {
             Value::Error { error } => Err(error),
             val => {