`RoomListLoadingState` was initialized with the `NotLoaded` state. This
is always true… except when there is a cache! If the cache contains
N rooms, the loading state should be `Loaded { … }`. Then the next
sync (if any) will update the loading state to `Loaded { … }` with
an adjusted number of rooms or something like that, but semantically
speaking, the presence of the cache should result in a `Loaded` state.
This patch fixes this behavior, and also adds the tests.
Ivan Enderlin
1cf5f3a0ee