Fix some of the inconsistencies in gnome 40

[AgathaSorceress]

An attempt at fixing the background color and the dash menu in gnome-shell v40. (#105) There are still quite a few new bugs which appeared after the update that I couldn't fix but this should at least fix the most obvious ones.

I'm not sure if I'll be able to fix more things with this PR (I'll try, at least), but here are some of the remaining bugs I've noticed so far:

• no visual response when selecting apps in dash, fullscreen app picker menu or hovering over search results
• the separator between pinned and unpinned apps in the dash doesn't seem to be themed
• the open folder menu in the app picker is no longer themed
• some visual small glitches due to the use of transparency in the overview menu
• the Gnome Terminal background tries to be transparent and breaks
• the default Extensions, GTK Demo, Icon Browser and Widget Factory apps are no longer themed
• workspace switcher at the top is too small and the empty space padding around workspaces in the middle is way too much (could be personal preference)
• some top bar buttons can get doubled highlighting on hover which sometimes doesn't go away when unhovered

[vltr]

This already makes a lot of things usable. One "big" change we got on Gnome Shell 40 is how the dock now have some different theme classes, as can be checked out here 😉

[menezesfelipee]

Perfect!!! Thank you!

[peterlobster]

This patch has some issues now applying...

git apply --check 106.patch
error: patch failed: gnome-shell/_common.scss:1378
error: gnome-shell/_common.scss: patch does not apply
error: patch failed: gnome-shell/gnome-shell.css:1236
error: gnome-shell/gnome-shell.css: patch does not apply