Bulk completion criteria fix

[rtibbles]

Summary

Description of the change(s) you made

• Uses uniqWith to do a deep comparison of options objects
• If all options are not unique then just return nonUnique for the entire value passed into CompletionOptions
• Disable editing of learner managed when non-unique
• Ensure that the completionDropdown shows an empty placeholder, forcing the user to make a selection there first in bulk edits

Manual verification steps performed

1. Edit one item to have a specific set of completion criteria
2. Select two other items of the same kind that have a different criteria
3. Confirm that you can now (restrictedly) edit these in sync and have it persist

Screenshots (if applicable)

Screencast.from.11-04-2022.02.38.53.PM.webm.mp4

Does this introduce any tech-debt items?

This is not an ideal user experience, but doing it better would involve more specific reading and patching of the nested representations inside the options objects

Fixes #3794

[marcellamaki]

This seems to be a workable solution for now. Code is straightforward and better than doing a large revision, and manual QA checks out

[pcenov]

Tested and verified that this is implemented as specified, no issues observed.