Dungeons: Make multiple large rooms possible (#8678)

Dungeons: Make multiple large rooms possible (#8678)

Re-add the random size range for large rooms.
Remove 'first_room_large' bool.
Add 'large_room_chance' parameter that can disable large rooms,
specify 1 large room, or specify a chance for large rooms.
If 1 or a chance is specified, the first generated room is large,
to take advantage of the intersection checks that are done for the
1st room only.