Setting to show/hide terminal title (#8559)

This PR adds settings for hiding title (breadcrumbs) from the terminal
toolbar. If the title is hidden, the toolbar disappears completely.

Example:

```json
"terminal": {
  "toolbar": {
    "title": true,
  }
}
```

[The PR that added the "toolbar"
setting](https://github.com/zed-industries/zed/pull/7338) didn't affect
toolbars of the terminals that are placed in the editor pane. This PR
fixes that.


Release Notes:

- Added support for configuring the terminal toolbar ([8125](https://github.com/zed-industries/zed/issues/8125))

docs/src/configuring_zed.md

@@ -681,6 +681,9 @@ These values take in the same options as the root-level settings with the same n
   "font_size": null,
   "option_as_meta": false,
   "shell": {},
+  "toolbar": {
+    "title": true
+  },
   "working_directory": "current_project_directory"
 }
 ```
@@ -839,6 +842,22 @@ See Buffer Font Features
 }
 ```
 
+## Terminal Toolbar
+
+- Description: Whether or not to show various elements in the terminal toolbar. It only affects terminals placed in the editor pane.
+- Setting: `toolbar`
+- Default:
+
+```json
+"toolbar": {
+  "title": true,
+},
+```
+
+**Options**
+
+At the moment, only the `title` option is available, it controls displaying of the terminal title that can be changed via `PROMPT_COMMAND`. If the title is hidden, the terminal toolbar is not displayed.
+
 ### Working Directory
 
 - Description: What working directory to use when launching the terminal.