Fix comments on separators and handling message literals and compound strings in options

[doriable]

This fixes some issues in the formatter for handling trailing comments
on separators (, and ;) in message literals. These comments are added
to the element if the element itself did not have trailing comments. However,
the comments that were added to message and array literal elements are
"left behind" because they are not being handled. This PR adds logic that
handles these comments similar to how comments on separators are handled --
it checks array and message literals for any trailing comments that may have been
added in this manner and adds them to closing brackets, if the closing brackets
did not have comments originally. Tests have been added for these cases.

In the process of testing, we also found an additional bug, where empty message
literals were not being handled as compact messages and compound strings in
options were not being written with their ends in-line for trailing commas.

Fixes #3322

[github-actions]

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Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Sep 16, 2024, 9:54 PM

[bufdev]

Needs changelog