Draft: Mozilla91 v9

Containing patches for linux, windows, macos builds.

Closes #40347 (closed), #40044 (closed), #40222 (closed), #40305 (closed), #40306 (closed), #40307 (closed), #40357 (closed), #40048 (closed), #40361 (closed), #28240 (closed), #40334 (closed), #40048 (closed).

Replacing !343 (closed).