Extend admin frontend with duplication, copying, and progress operations

[neketka]

Summary

This pull request extends the admin frontend to add more useful features.

• Added websocket acknowledgements for all gateway functions (to indicate modified ids/success/modified count)
• Copy events to other organizations
• Copy achievements to other organizations
• Copy challenges to other events
• Add members to organization

Remaining TODOs:

• View progress screen for looking at event trackers in an event

Test Plan

Test the admin frontend to make sure all these features work correctly.

[dti-github-bot]

[diff-counting] Significant lines: 903.

[cathli66]

Tested all copying on the admin frontend and joining orgs in the backend. There was an issue with CASL permissions (users could not read their auth type), but went ahead and fixed that! Everything looks great :)
LAST BIG PR!!