fix: crash overview on 4x when min tray enabled and remove dupe app icons on switch-app

[jmmaranan]

Hopefully fixes #1251 for gnome 4x users. This should enable 4x to see the overview for minimized to tray apps and corresponding windows. E.g. Sleek used as a minimized to tray app

Also fixes #1094 - remove the duplicate app icons introduced by adding skip task bar windows. This also makes skip-task-bar windows behave as if they are normal icons on the switcher (if have multiple associated windows, they get the same treatment as normal - shows an arrow icon when Sleek has multiple open instances)

On Gnome 4x:

On Gnome 3x:

[Arcitec]

@mmstick Hey, just a small heads-up that it's not merge ready. Code review comments above below (😆) mention at least 1 bug introduced by these changes. Possibly 2 bugs. And the window type check needs a small adjustment to actually exclude OR windows. Other than that it looks very good. Just some small adjustments necessary.

[jmmaranan]

@Bananaman - do you know where those code review comments are at? Don't see them here on this PR.

[Arcitec]

Here's the code review. Sorry, it's been a while since I used GitHub and they've changed how code reviews work. It turns out that I had to go in and submit the whole batch of comments with an extra click. :)

[jmmaranan]

Thanks for the review. I will get coding tomorrow when time permits

[Arcitec]

Thanks for the review. I will get coding tomorrow when time permits

And thank you very much for tackling these issues! Pop Shell is a fantastic extension, so it's great that we are close to stopping these crashes. :)

[jacobgkau]

This fixes #1094. There is no longer a second Android Studio entry in the Alt-Tab application switcher when an emulator is running. (21.10 & 20.04)

Sleek with Minimize to Tray enabled still shows up in the overview, is still tiled/gets an active hint, can still be moved/resized using the keyboard, and still shows up in the Alt-Tab application switcher. (21.10 & 20.04)

From what I understand, #1251 was already mitigated by #1249, but this new solution doesn't require doing as much version checking, is more correct, and will thus be easier to maintain.

Regression testing passed:
shell-pr1255-impish.txt
shell-pr1255-focal.txt