refactor: use async-aware RwLocks and Mutexes where possible

src/api/client_server/keys.rs

src/api/client_server/media.rs

src/api/client_server/membership.rs

src/api/client_server/message.rs

src/api/client_server/profile.rs

src/api/client_server/redact.rs

src/api/client_server/room.rs

src/api/client_server/state.rs

src/api/client_server/sync.rs

src/api/server_server.rs

src/lib.rs

src/service/admin/mod.rs

src/service/globals/mod.rs

src/service/media/mod.rs

src/service/mod.rs

src/service/rooms/event_handler/mod.rs

src/service/rooms/lazy_loading/mod.rs

src/service/rooms/spaces/mod.rs

src/service/rooms/state/mod.rs

src/service/rooms/timeline/mod.rs