Map submission fixes

[tsa96]

Misc fixes for stuff that broke last QnA

Based on top of https://github.com/momentum-mod/website/pull/999, that should be reviewed first.

Checks

• [x] I have included/updated tests where applicable (see Testing)
• [x] I have ran nx run db:create-migration and committed the migration if I've made DB schema changes
• [x] I have followed semantic commit messages e.g. feat: Add foo, chore: Update bar, etc...
• [x] My branch has a clear history of changes that can be easy to follow when being reviewed commit-by-commit
• [x] My branch is functionally complete; the only changes to be done will be those potentially requested in code review
• [x] All changes requested in review have been fixuped into my original commits