Enable nested to-many in Workbench

[sharadsw]

Fixes #2331

Warning

This PR is based on #5417. Use either a db that was used to test #5417 or create a new db

This PR enables nested to many in the data mapper and fixes some automated tests. The underlying backend support for nested to many is in #5417.

For reference:
Nested to-manys in the workbench are mapping lines that involve multiple to-many relationships. For example: Collection Object -> Determination (to many) -> DeterminationCitation (to-many) -> ...

Checklist

• Self-review the PR after opening it to make sure the changes look good and
  self-explanatory (or properly documented)
• Add automated tests
• Add relevant issue to release milestone
• Add relevant documentation (Tester - Dev)
• Add a reverse migration if a migration is present in the PR

Testing instructions

• Create a Workbench dataset
• Map columns that include nested to-manys
  • Examples:
    • CO -> Determination -> DeterminationCitation (see above)
    • CO -> Preparation -> PreparationProperty
    • CO -> Preparation -> PreparationAttribute
• Enter data
• Test upload
• Verify data was uploaded correctly (you can verify through queries)
• Test rollback

[lexiclevenger]

• Test upload
• Verify data was uploaded correctly (you can verify through queries)
• Test rollback

---

Looks good! I tested CO -> Determination -> DeterminationCitation and CO -> Preparation -> PreparationAttribute

[emenslin]

• Test upload
• Verify data was uploaded correctly (you can verify through queries)
• Test rollback

Looks good, it seems like the RS owner issue was reintroduced in this PR though.

Issue branch:

03-05_14.14.mp4

Production:

03-05_14.20.mp4

[sharadsw]

@emenslin Should be fixed now. The branch didn't have the latest production changes

[emenslin]

• Test upload
• Verify data was uploaded correctly (you can verify through queries)
• Test rollback

Looks good now!