Create ModerationDecision table

[sarayourfriend]

Description

The plan for this has been modified slightly from the description in the IP based on the subsequent Bulk actions IP, so the full description (including updates) is written out below. Where it differs from the IP I have bolded the text so it is easier to see.

• Create the new ModerationDecision model with the following columns:
  • id: basic auto-incrementing id
  • created_on: the date the moderation decision was created, in other words, the date the decision was made
    • Provided by OpenLedgerModel
  • moderator_id: a foreign key relationship with moderator who made the decision
  • media_identifiers: a many-to-many relationship to the media the decision is related to, implemented by a join table.
    • Because deindexing media removes them from the API database, the identifiers needs to be non-constrained, so not a foreign key, just an indexed non-unique UUID column using the db_constrained argument
  • explanation: moderator notes explaining the decision; optional
  • action: slug column of the action taken
    • marked_sensitive (marked a work as sensitive)
    • deindexed_copyright (deindexed the work from Openverse search due to copyright)
    • deindexed_sensitive (deindexed the work from Openverse search due to sensitivity)
    • rejected_reports (the reviewed reports were rejected)
    • deduplicated_reports (the reviewed reports were marked as duplicates, in other words, re-reports that did not result in deindexing but were also accurate, for example, re-reports of a sensitive work that add information regarding sensitivity but do not require deindexing)
    • reversed_deindex (undo a previous deindexing decision)
    • reversed_mark_sensitive (undo a previous decision marking the record sensitive)
• Create an AbstractModerationDecision for each media type
• Add new nullable decision_id column to the Report models
• Remove all logic from the Report models’ save methods

Blocks #3638, #3641, #3840, and #3844

[dhruvkb]

This is blocked on #3719 which enables plural media identifiers and adds additional actions for the decision model.

[stacimc]

#3840 has been merged. I've updated the description and removed the blocked label.

[sarayourfriend]

Thank you, Staci!