[Bug] Slicing a room in two does not create separate rooms

[Cerzi]

Steps to reproduce:
- Drag out a large room (eg yard)
- Use right click drag to cut through the middle of the room

Result:
- The blueprint-style text does not get repositioned, and there are now 2 separate rooms under the same designation
- You can continue to remove tiles, as long as you leave the top left and bottom right tiles the text will remain in the same position / size.

NOTE: This also gets around minimum room sizes, as a "room" consisting of just two 1x1 tiles far enough apart will still meet the minimum room size. eg. a 10x10 yard whittled down to 2 tiles (one at top left, one at top right) is still considered a single 10x10 room.

Considering that two rooms are merged together when they become adjacent (eg two yards joined together by yard tiles become a single yard), I'm assuming that removing tiles from a single room such that it becomes two separate rooms is the intended functionality.