Reimplement "Add option to make all window in overview be rounded"

[sidevesh]

Closes #93

[ifelsemaybe]

Works on my machine.

[sidevesh]

I have just migrated the original code written by @yilozt on a branch but never merged to Gnome 45,
not sure why @yilozt is non responsive on this since almost a year despite writing the original code and taking the effort to upgrade the extension to Gnome 45 a while back.
@yilozt It would be great if you can merge this in so I can stop having to maintain this branch.

[ifelsemaybe]

They might just be busy. Sometimes life gets in the way man.

[ifelsemaybe]

Actually, one bug I'm noticing with your branch is that when I go in the overview, all the windows are blurred for some reason. If I disable the "Add rounded corners for all windows in overview" setting, inside Extensions, that blur disappears. So something is up. While scrolling through the commit history, I saw that this bug has been addressed before, 02f0ae8. Maybe this can offer some insight...

[ifelsemaybe]

While testing this issue a little further, I believe the blur shows itself in the overview to all windows that have rounded corners. So on the main branch, a window that has not been maximized, and shows up by default, rounded, in the overview, will also have this same problem. I might raise an issue for this, if it hasn't already been raised.