Make MRF and Quarantine work with tuples
The idea is to also give a reason instead of only a list of rejected/muted/etc. instances.
Most of the changes are done in the BE, but some are done here.
- Change in the admin-fe to make tuples properly work for MRF and Quarantine
- Give other names to 'Key' and 'Value'
- Backwards compat (This version should still work on an old pleroma)