Support bracket colorization (rainbow brackets) (#43172)

Deals with https://github.com/zed-industries/zed/issues/5259

Highlights brackets with different colors based on their depth.
Uses existing tree-sitter queries from brackets.scm to find brackets,
uses theme's accents to color them.


https://github.com/user-attachments/assets/cc5f3aba-22fa-446d-9af7-ba6e772029da

1. Adds `colorize_brackets` language setting that allows, per language
or globally for all languages, to configure whether Zed should color the
brackets for a particular language.

Disabled for all languages by default.

2. Any given language can opt-out a certain bracket pair by amending the
brackets.scm like `("\"" @open "\"" @close) ` -> `(("\"" @open "\""
@close) (#set! rainbow.exclude))`

3. Brackets are using colors from theme accents, which can be overridden
as

```jsonc
"theme_overrides": {
  "One Dark": {
    "accents": ["#ff69b4", "#7fff00", "#ff1493", "#00ffff", "#ff8c00", "#9400d3"]
  }
},
```

Release Notes:

- Added bracket colorization (rainbow brackets) support. Use
`colorize_brackets` language setting to enable.

---------

Co-authored-by: MrSubidubi <dev@bahn.sh>
Co-authored-by: Lukas Wirth <lukas@zed.dev>
Co-authored-by: MrSubidubi <finn@zed.dev>
Co-authored-by: Lukas Wirth <me@lukaswirth.dev>
Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>

docs/src/themes.md

@@ -51,7 +51,15 @@ For example, add the following to your `settings.json` if you wish to override t
         "comment.doc": {
           "font_style": "italic"
         }
-      }
+      },
+      "accents": [
+        "#ff0000",
+        "#ff7f00",
+        "#ffff00",
+        "#00ff00",
+        "#0000ff",
+        "#8b00ff"
+      ]
     }
   }
 }