Reduce garbage collection

[Hachitus]

Especially in map movement and fog of war extensions, since those are the 2 most resource heavy parts. But elsewhere too.

The memory is not the issue in the game, but rather CPU and GPU efficiency. Doing garbage collection too often will slow down the javascript. There should be optimal efficiency for tasks. Remember to prioritize efficiency over memory-usage.

You can use stunts like object pooling (e.g. https://github.com/Nazariglez/obj-pool/blob/master/README.md), memoization etc. as you see most efficient.

Before you start optimizing, you should already take up performance results and compare them when doing the task and when the task is done. So we have better idea how much the efficiency has improved.