fully deprecate str collect (#8680)

# Description

This PR fully deprecates `str collect`. It's been "half-deprecatd" for a
long time. This takes it all the way and disallows the command in favor
of `str join`.

# User-Facing Changes

No more `str collect`

# 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
- `cargo run -- crates/nu-utils/standard_library/tests.nu` to run the
tests for the standard library

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```

# 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/collect.rs

@@ -0,0 +1,34 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Category, PipelineData, ShellError, Signature};
+
+#[derive(Clone)]
+pub struct StrCollectDeprecated;
+
+impl Command for StrCollectDeprecated {
+    fn name(&self) -> &str {
+        "str collect"
+    }
+
+    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(),
+            "str join".to_owned(),
+            call.head,
+        ))
+    }
+}

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

@@ -23,5 +23,6 @@ pub fn deprecated_commands() -> HashMap<String, String> {
         ("str lpad".to_string(), "fill".to_string()),
         ("str rpad".to_string(), "fill".to_string()),
         ("benchmark".to_string(), "timeit".to_string()),
+        ("str collect".to_string(), "str join".to_string()),
     ])
 }

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

@@ -1,3 +1,4 @@
+mod collect;
 mod deprecated_commands;
 mod export_old_alias;
 mod hash_base64;
@@ -11,6 +12,7 @@ mod str_decimal;
 mod str_find_replace;
 mod str_int;
 
+pub use collect::StrCollectDeprecated;
 pub use deprecated_commands::*;
 pub use export_old_alias::ExportOldAlias;
 pub use hash_base64::HashBase64;