Exclude deprecated commands from completions (nushell#9612)

# Description
We previously simply searched all commands in the working set. As our
deprecated/removed subcommands are documented by stub commands that
don't do anything apart from providing a message, they were still
included.
With this change we check the `Signature.category` to not be
`Category::Deprecated`.

## Note on performance
Making this change will exercise `Command.signature()` more
frequently! As the rust-implemented commands include their builders here
this probably will cause a number of extra allocations. There is
actually no valid reason why the commands should construct a new
`Signature` for each call to `Command.signature()`.
This will introduce some overhead to generate the completions for
commands.
# User-Facing Changes
Example: `str <TAB>`


![grafik](https://github.com/nushell/nushell/assets/15833959/4d5ec5fe-aa93-45af-aa60-3854a20fcb04)

Author: sholderbach

crates/nu-cli/src/completions/command_completions.rs

@@ -89,7 +89,7 @@ impl CommandCompletion {
         let filter_predicate = |command: &[u8]| match_algorithm.matches_u8(command, partial);
 
         let mut results = working_set
-            .find_commands_by_predicate(filter_predicate)
+            .find_commands_by_predicate(filter_predicate, true)
             .into_iter()
             .map(move |x| Suggestion {
                 value: String::from_utf8_lossy(&x.0).to_string(),

crates/nu-protocol/src/engine/engine_state.rs

@@ -6,7 +6,7 @@ use crate::{
     ast::Block, BlockId, Config, DeclId, Example, FileId, Module, ModuleId, OverlayId, ShellError,
     Signature, Span, Type, VarId, Variable, VirtualPathId,
 };
-use crate::{ParseError, Value};
+use crate::{Category, ParseError, Value};
 use core::panic;
 use std::borrow::Borrow;
 use std::collections::{HashMap, HashSet};
@@ -708,13 +708,17 @@ impl EngineState {
     pub fn find_commands_by_predicate(
         &self,
         predicate: impl Fn(&[u8]) -> bool,
+        ignore_deprecated: bool,
     ) -> Vec<(Vec<u8>, Option<String>)> {
         let mut output = vec![];
 
         for overlay_frame in self.active_overlays(&[]).rev() {
             for decl in &overlay_frame.decls {
                 if overlay_frame.visibility.is_decl_id_visible(decl.1) && predicate(&decl.0 .0) {
                     let command = self.get_decl(*decl.1);
+                    if ignore_deprecated && command.signature().category == Category::Deprecated {
+                        continue;
+                    }
                     output.push((decl.0 .0.clone(), Some(command.usage().to_string())));
                 }
             }
@@ -1755,6 +1759,7 @@ impl<'a> StateWorkingSet<'a> {
     pub fn find_commands_by_predicate(
         &self,
         predicate: impl Fn(&[u8]) -> bool,
+        ignore_deprecated: bool,
     ) -> Vec<(Vec<u8>, Option<String>)> {
         let mut output = vec![];
 
@@ -1766,13 +1771,19 @@ impl<'a> StateWorkingSet<'a> {
                     if overlay_frame.visibility.is_decl_id_visible(decl.1) && predicate(&decl.0 .0)
                     {
                         let command = self.get_decl(*decl.1);
+                        if ignore_deprecated && command.signature().category == Category::Deprecated
+                        {
+                            continue;
+                        }
                         output.push((decl.0 .0.clone(), Some(command.usage().to_string())));
                     }
                 }
             }
         }
 
-        let mut permanent = self.permanent_state.find_commands_by_predicate(predicate);
+        let mut permanent = self
+            .permanent_state
+            .find_commands_by_predicate(predicate, ignore_deprecated);
 
         output.append(&mut permanent);