Fix mutable priority queue being wiped when moving out of function
Without move constructor, the clean() gets called when returning an instance from a function.
The above fix was applied also to MutableSkipHeapPriorityQueue.
Follow-up to 15a082b80b1d9ed3cfa70d3d8133c4cd1e5d699d:
Fixed TEST_CASE("Mutable priority queue - first pop", "[MutableSkipHeapPriorityQueue]")
Improved readability by introducing invalid_id() getter.
Made the ResetIndexWhenRemoved flag active in both debug and release mode,
it used to be made active by Vojtech for release mode only for unknown
reason.
producing better shortest path estimate than the "closest next neighbor"
heuristics. The new greedy algorithm utilizes KD tree for closest
end point search, and builds a graph to detect loops.
PerimeterGenerator newly uses the optimized TSP algorithm.
ExtrusionEntity has been refactored / simplified.
