refactor: work on search

src/database/key_value/room.rs

src/database/key_value/rooms/alias.rs

src/database/key_value/rooms/directory.rs

src/database/key_value/rooms/edus/presence.rs

src/database/key_value/rooms/edus/read_receipt.rs

src/database/key_value/rooms/edus/typing.rs

src/database/key_value/rooms/lazy_load.rs

src/database/key_value/rooms/metadata.rs

src/database/key_value/rooms/mod.rs

src/database/key_value/rooms/outlier.rs

src/database/key_value/rooms/pdu_metadata.rs

src/database/key_value/rooms/search.rs

src/database/key_value/rooms/state.rs

src/service/rooms/search/data.rs

src/service/rooms/search/mod.rs

src/service/rooms/timeline/mod.rs