Return IJoinedRoomsResponse from getJoinedRooms(), instead of string[]
Return IJoinedRoomsResponse from getJoinedRooms(), instead of string[]

Signed-off-by: Paulo Pinto <54cf591bad4c0a338cd6ca49bee56cb2238be636@automattic.com>

matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk