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))