Relevant MSC:
https://github.com/Zocker1999NET/matrix-spec-proposals/blob/user-nicknames/proposals/3865-user-nicknames.md
- [x] Parsing (D37)
- [x] Show overrided names for users (D38)
- [x] Support editing overrided names (D39)
- [ ] Show overrided names in room heroes
- [ ] Support filtering rooms by heroes' overrided names