Make Merging User Profiles available in UI for Admins

[sc-ivanlieckens]

Is your feature request related to a problem? Please describe. Users have issues with their Okta, changing emails and various profiles leading to multiple profiles on the MVP side. Recently #354 displayed this. As an admin I want to merge these easily from the UI instead of having to use postman API calls.

Describe the solution you'd like Allow selecting 2 users in the UI to merge and providing the necessary insights to choose the surviving record.

Describe alternatives you've considered

Additional context