[feature] - user photo

### What

This is a WIP (mostly awaiting for feedback) to handle user profile photos.

It makes use of Media Sources (using the default one per default, but configurable using the `photo_profile_source` system setting -- expecting a media source ID).

### To do before merge

- [ ] create lexicon string for the system setting
- [ ] replicate the UI on security/profile so users

### Related issue(s)

#11824