Create a new room in a space (#6061)

* Add `SpaceService.editableSpaces` and `SpaceService.addChildToSpace`

* Add `parentSpace` to `CreateRoomConfig`

* Allow setting a parent space to a room in `ConfigureRoomPresenter`, make sure the room is added to the parent space when creating it

* `ConfigureRoomPresenter`: Load the list of possible spaces a room can be added to

* Refactor `RoomVisibilityState` to internally use `JoinRuleItem`

This gets rid of `RoomAccess` and `RoomAccessItem`, and it will allow us to map the join rule items in a cleaner way to both join rules and the UI

* Implement the UI changes:

- Display the parent space.
- Allow selecting a new one.
- Import needed strings.

* Fix existing tests

* Add `@Immutable` annotation to `SpaceRoom`, since it was detected as unstable.

Maybe because of `RoomType`?

* Update screenshots

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Co-authored-by: ElementBot <android@element.io>

libraries/designsystem/src/main/kotlin/io/element/android/libraries/designsystem/components/avatar/AvatarSize.kt

@@ -74,6 +74,7 @@ enum class AvatarSize(val dp: Dp) {
     RoomPreviewInviter(56.dp),
     SpaceMember(24.dp),
     LeaveSpaceRoom(32.dp),
+    SelectParentSpace(32.dp),
 
     AccountItem(32.dp),
 }