fix(dav): Run system address book create-if-not-exists in transaction

[ChristophWurst]

Summary

This might break in clustered DB setup

@CarlSchwan Jun 24, 2022

TODO

• [x] Wrap business transactions in database transactions

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• [x] Tests (unit, integration, api and/or acceptance) are included
• [x] Screenshots before/after for front-end changes
• [x] Documentation (manuals or wiki) has been updated or is not required
• [ ] Backports requested where applicable (ex: critical bugfixes)

[tcitworld]

Tests need to be fixed

[ChristophWurst]

Tests fail because I made the class strict. Yay.

[ChristophWurst]

nodb tests fail

[szaimen]

CI failure unrelated