Fix alembic migrations

[mesemus]

Description

This PR fixes alembic problems in migrations of invenio-communities:

• adds linearization of the order of migrations that was having problems with the change of accounts_role from integer to string
• adds missing migrations
• adds tests for migrations

See inveniosoftware/product-rdm#242 for details.

Checklist

Ticks in all boxes and 🟢 on all GitHub actions status checks are required to merge:

• I'm aware of the code of conduct.
• I've created logical separate commits and followed the commit message format.
• I've added relevant test cases.
• I've added relevant documentation.
• I've marked translation strings.
• I've identified the copyright holder(s) and updated copyright headers for touched files (>15 lines contributions).
• I've NOT included third-party code (copy/pasted source code or new dependencies).
  • If you have added third-party code (copy/pasted or new dependencies), please reach out to an architect on Discord.

Frontend

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[utnapischtim]

combined with #1355 into #1385