[3006.x] maintain user-defined options in apt source definitions

[s0undt3ch]

What does this PR do?

Port #65366 to 3006.x

Attempts to maintain all debian source options (not just arch and signed-by) from debian package repo definitions.

NOTE: Through testing it was observed that Salt was also removing options from sources list files that were not even managed by Salt (because it reads all *.list files in known apt locations and re-writes them). This PR doesn't fix the behavior of Salt re-writing all *.list files, but it should prevent Salt from blindly stripping out options in those files.

What issues does this PR fix or reference?

Fixes: #64130

Previous Behavior

A pkgrepo definition like this:

test_unsigned_repo:
  pkgrepo.managed:
    - humanname: unsigned_repo
    - name: deb [trusted=yes] http://reposerver.net/ubuntu main
    - file: /etc/apt/sources.list.d/unsigned_repo_test

Resulted in a source list file like this (missing [trustred=yes] option):

deb http://reposerver.net/ubuntu main

New Behavior

A pkgrepo definition like this:

test_unsigned_repo:
  pkgrepo.managed:
    - humanname: unsigned_repo
    - name: deb [trusted=yes] http://reposerver.net/ubuntu main
    - file: /etc/apt/sources.list.d/unsigned_repo_test

Results in a correct source list file like this ([trustred=yes] option is maintained):

deb [trusted=yes] http://reposerver.net/ubuntu main

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• Docs- Didn't seem to me like docs needed updated for this change
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

Commits signed with GPG?

No

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