wf-panel does not lose keyboard focus when closing menu

[dkondor]

Describe the bug
I found it nice to have the new feature to open / close the menu with a keyboard shortcut (from #2097), but I found that when closing the menu with the keyboard, the panel retains the keyboard focus. To me, the natural behavior would be that the last focused app gets back the focus. I feel that this is actually the intended behavior, since wf-panel sends a zwlr_layer_surface_v1#40.set_keyboard_interactivity(0) request when the menu is closed. Also here, it is indicated that a refocus might happen as a consequence of changing keyboard-interactivity, but the arrange_layers() function does not seem to handle focus changes.

To Reproduce
Steps to reproduce the behavior:

1. Run wf-panel and open the menu (with at least one open view).
2. Close the menu with keyboard interaction (pressing ESC, or the shortcut set for wayfire-shell/toggle_menu).
3. The panel keeps keyboard focus.

Expected behavior
The last focused view gets back the keyboard focus.

Wayfire version
latest git (9c9630d)

[ammen99]

That comment which says rearranging the layers will update cursor focus seems quite outdated. We probably need to simply refocus at the end of the function, if the interactivity has changed. We already have one such check, so probably it should just be extended to handle more cases.

[soreau]

Seems like a duplicate of #2047.