Closes https://github.com/zed-industries/zed/issues/10140

* On `menu::Cancel` action (`ESC`), close notifications, one by one, if
`Workspace` gets to handle this action.
More specific, focused items contexts (e.g. `Editor`) take priority.

* Allows to temporarily suppress notifications of this kind either by
clicking a corresponding button in the UI, or using
`workspace::SuppressNotification` action.

This might not work well out of the box for all notifications and might
require further improvement.


https://github.com/user-attachments/assets/0ea49ee6-cd21-464f-ba74-fc40f7a8dedf


Release Notes:

- Added a way to dismiss workspace notifications