Gnome-shell: Drop Heavy Modifications - Focus on colors

[ochi12]

currently there are a lot of inconsistencies specially in gnome shell, mainly border radii. I think sharper corners already look outdated (e.g. yaru themed quick settings). We should just keep the upstream gnome-shell theme and focus on colors.

[Muqtxdir]

Hey @ochi12 have you seen #4338 PR - would love to hear your thoughts, I had the same intentions as you pointed out in the issue description