feat(ffi) Update RoomList API to the recent changes.

This patch adapts the `RoomList` FFI API to the recent changes to
suport a `Stream<Item = RoomListItem>` instead of a `Stream<Item =
RoomListEntry>`. Behind the scene, it supports client side sorting for
the rooms but this is transparent for this API.

This patch also removes the `RoomListInput` enum as no input is
supporter anymore.

The `entries` method no long returns a `RoomListEntriesResult` but
directly a `TaskHandle`. The given listener will receive the initial
entries as a `VectorDiff::Append`, which first is simpler but also fixe
a potential race condition bug.