Migrated legacy libraries are still editable

[kdmccormick]

The issue

• Create a legacy library with at least one block
• Create 2 legacy references to it in a course
• Migrate the legacy library to a v2 library
• Convert 1 of the 2 legacy course references to the "new format"
• Observe that you can now edit the library in two divergent ways:
  • You can edit the original legacy library content in the legacy experience
  • You can edit the migrated content in the V2 experience
• Also observe that:
  • Your legacy reference will prompt for updates from the legacy library
  • Your converted reference will prompt for updates from the V2 library

Basically, you end up with 2 libraries, forked at the point of migration.

Recommended solution

Two suggestions:

1. Legacy references should not check for updates fro the legacy library. They should just prompt to be converted to the new format, so that they can prompt for updates from the V2 library.
2. Migrated legacy libraries should not be viewable or editable. They should just redirect you to their migrated collection in their target V2 library.