feat(room): add `JoinRequest` subscriptions #13208

Job	Run time
Generate Crypto FFI Apple XCFramework	6m 52s
Run Complement Crypto tests / tests	7m 55s
xtask / xtask-🐧	6s
xtask / xtask-🍏	8s
Test UniFFI bindings generation	2m 13s
matrix-rust-components-swift	19m 27s
matrix-rust-components-kotlin	5m 44s
	42m 25s

Provide feedback