Bug 42276: Rebase alpha onto 115.5.0esr

Rebased the alpha onto 115.5.0esr (#42276 (closed)).

The diff of diffs is almost clean, except for the reversed order of

      () => ClipboardPrivacy.emptyPrivate(), // tor-browser#42019
      () => lazy.OnionAliasStore.uninit(),

which I reversed to be coherent with the stable.

The range-diff is... something, here are two suggestions:

• 13.0-1-build1 and 13.5-1-build1 were the same tags, so the commits to squash were the same. You might find it easier to range-diff between 115.5 stable and this branch
• TIL range-diff becomes much easier to deal with if you reverse the ranges: if you do git range-diff FIREFOX_115_5_0esr_BUILD1..pierov/bug_42276 FIREFOX_115_4_0esr_BUILD1..upstream/tor-browser-115.4.0esr-13.5-1 you will get all the fixups we intend to keep at the end, and all in progressive number (if your pager is less, you can skip to the end with G - capital G - and go backward, at a certain point you won't see any more fixup)

/cc @richard @ma1