Profiles: Add status and call fields to room heroes.

[pixlwave]

Builds on top of #6704 (directly targets that branch) and makes the same changes for Room Heroes. I've done this one separately as this PR makes Room::heroes() async and changes the return type so I'm less confident of the approach and don't want to block the previous one from being merged on a discussion about heroes.

• I've documented the public API changes in the appropriate changelog files (see Writing changelog entries).
• This PR was made with the help of AI.

[pixlwave]

Claude kept trying to convince me to use RoomHero with a #[serde(skip)] on the profile fields but that felt all kinds of wrong to me so I settled on this route with distinct types for storage vs data transfer.

Happy to change if this isn't desirable though.

[codspeed-hq]

Merging this PR will not alter performance

✅ 50 untouched benchmarks

---

_{Comparing doug/hero-user-status (4d89085) with main (afc182e)}

[codecov]

Codecov Report

❌ Patch coverage is 91.61290% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.93%. Comparing base (afc182e) to head (4d89085).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
crates/matrix-sdk-base/src/room/display_name.rs	61.11%	7 Missing ⚠️
crates/matrix-sdk-base/src/room/mod.rs	95.23%	3 Missing and 1 partial ⚠️
crates/matrix-sdk-base/src/sliding_sync.rs	97.43%	1 Missing ⚠️
crates/matrix-sdk-ui/src/spaces/room.rs	85.71%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main    #6733    +/-   ##
========================================
  Coverage   89.93%   89.93%            
========================================
  Files         398      398            
  Lines      111492   111637   +145     
  Branches   111492   111637   +145     
========================================
+ Hits       100269   100402   +133     
- Misses       7418     7427     +9     
- Partials     3805     3808     +3     

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