Introduce settings profiles (#35339)

Settings Profiles

- [X] Allow profiles to be defined, where each profile can be any of
Zed's settings
    - [X] Autocompletion of all settings
    - [X] Errors on invalid keys
- [X] Action brings up modal that shows user-defined profiles
- [X] Alphabetize profiles
- [X] Ability to filter down via keyboard, and navigate via arrow up and
down
- [X] Auto select Disabled option by default (first in list, after
alphabetizing user-defined profiles)
- [X] Automatically select active profile on next picker summoning
- [X] Persist settings until toggled off
- [X] Show live preview as you select from the profile picker
- [X] Tweaking a setting, while in a profile, updates the profile live
- [X] Make sure actions that live update Zed, such as `cmd-0`, `cmd-+`,
and `cmd--`, work while in a profile
- [X] Add a test to track state

Release Notes:

- Added the ability to configure settings profiles, via the "profiles"
key. Example:

```json
{
  "profiles": {
    "Streaming": {
      "agent_font_size": 20,
      "buffer_font_size": 20,
      "theme": "One Light",
      "ui_font_size": 20
    }
  }
}
```

To set a profile, use `settings profile selector: toggle`

crates/zed/Cargo.toml

@@ -106,6 +106,7 @@ outline_panel.workspace = true
 parking_lot.workspace = true
 paths.workspace = true
 picker.workspace = true
+settings_profile_selector.workspace = true
 profiling.workspace = true
 project.workspace = true
 project_panel.workspace = true

crates/zed/src/main.rs

@@ -613,6 +613,7 @@ pub fn main() {
         language_selector::init(cx);
         toolchain_selector::init(cx);
         theme_selector::init(cx);
+        settings_profile_selector::init(cx);
         language_tools::init(cx);
         call::init(app_state.client.clone(), app_state.user_store.clone(), cx);
         notifications::init(app_state.client.clone(), app_state.user_store.clone(), cx);

crates/zed/src/zed.rs

@@ -4366,6 +4366,7 @@ mod tests {
                 "repl",
                 "rules_library",
                 "search",
+                "settings_profile_selector",
                 "snippets",
                 "supermaven",
                 "svg",