CLDR-17220 SBRS v45 merge selected maint/maint-44 fixes back to main

[pedberg-icu]

CLDR-17220

• This PR completes the ticket.

This merges relevant fixes on the maint/maint-44 branch back to main. Notes:

• The maint/maint-44 branch was created on Oct 11 after commit e58b346 of Oct 10
• This merge includes everything on the maint/maint-44 branch after the above commit, up through commit fa9259f of Oct 30, except for the specific items listed in the next sections.
• The following commits on maint/maint-44 were not included because they were cherry-picks to maint/maint-44 of fixes that had already been made on main:
  • Commit 32a1842 Oct 11, 2 keyboard spec fixes
  • Commit fc7cf41 Oct 11, 1 keyboard spec fix
• The following commits on maint/maint-44 were not included because they were specifically about updating various items to final status. On the main branch, we want to keep non-final status, but will update the version numbers for 45 under a separate PR.
  • Commit c291c05 Oct 25, remove -SNAPSHOT in poms, updated README to final
  • Commit 6e3f841 Oct 26, update spec status to final (but there are a few other specific fixes here that will be rolled in when I do the version number update)
  • Commit 19406a1 Oct 27, use final ICU4J libs

We probably want to merge this with a Rebase and merge (temporarily enable in Settings) instead of the usual Squash and merge.

ALLOW_MANY_COMMITS=true
DISABLE_JIRA_ISSUE_MATCH=true

[btangmu]

LGTM though I'm unfamiliar with most of this code

[btangmu]

dead code like this generally shouldn't be kept unless accompanied by an explanatory comment, preferably a TODO comment with an open ticket number, otherwise it leads to unmaintainable code

[pedberg-icu]

Agreed, but fixing those kinds of things probably does not belong in this kind of PR which is just merging maint branch changes back to main as is.