Adds settings for hiding breadcrumbs and quick action bar from
the editor toolbar. If both elements are hidden, the toolbar disappears
completely.
Example:
```json
"toolbar": {
"breadcrumbs": true,
"quick_actions": false
}
```
- It intentionally doesn't hide breadcrumbs in other views (for
instance, in the search result window) because their usage there differ
from the main editor.
- The editor controls how breadcrumbs are displayed in the toolbar, so
implementation differs a bit for breadcrumbs and quick actions bar.
Release Notes:
- Added support for configuring the editor toolbar ([4756](https://github.com/zed-industries/zed/issues/4756))
8da6e62914