After English, reorder languages alphabetically by language code

[tdonohue]

Description

Our list of languages has turned into a bit of a random ordering. In order to have consistency & make languages easier to locate, this PR reorders all languages after English alphabetically by their language code.

This also adds ar to the default-app-config.ts as it was missing there.

[kanasznagyzoltan]

We have tested this PR and compared the order of the languages using the main branch and using this PR branch.

The main branch:

The order of the languages using this PR branch:

Looks like the languages are indeed reordered by their language codes. Only exception is the two Portugese options. The language code of “Português” (pt-PT) alphabetically comes after the language code of “Português do Brasil” (pt-BR). I suppose this was done on purpose so the original Portugese comes before the Brazilian version, just thought I would mention it.

[tdonohue]

Merging as this had testing/verification from @kanasznagyzoltan . Thanks @kanasznagyzoltan !

[dspace-bot]

Backport failed for dspace-7_x, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin dspace-7_x
git worktree add -d .worktree/backport-3007-to-dspace-7_x origin/dspace-7_x
cd .worktree/backport-3007-to-dspace-7_x
git switch --create backport-3007-to-dspace-7_x
git cherry-pick -x 437cc5991eb1bddb010bf4f1e189f938356bc6e6

[tdonohue]

Ported to 7.x in #3042