Closes https://github.com/zed-industries/zed/issues/4566

Pane tabs (does not exist for multibuffer tabs):
<img width="439" alt="Screenshot 2024-04-18 at 23 01 08"
src="https://github.com/zed-industries/zed/assets/2690773/3af79ed8-07ea-4cf2-bcf9-735b1b3be8c4">

Editor context menu:
<img width="404" alt="Screenshot 2024-04-18 at 23 01 14"
src="https://github.com/zed-industries/zed/assets/2690773/38ea7afc-df2b-45ef-8331-eb6a4588af9f">

Project panel context menu (was not shown for file entries before this):
<img width="408" alt="Screenshot 2024-04-18 at 23 01 18"
src="https://github.com/zed-industries/zed/assets/2690773/e336fce1-7da0-4671-b8d2-8d3409c23eb6">

Release Notes:

- (breaking change) Moved `project_panel::OpenInTerminal` into
`workspace::OpenInTerminal` action and add it in editors, tab context
menus and proper panel file entries
([4566](https://github.com/zed-industries/zed/issues/4566))