fix: Active cooler can only touch active cooler of the same type

[pgelinas]

Added an additional check for active cooler that should only touch other active cooler of the same type, otherwise it's an invalid placement.

Also added a slight optimization to the accessibility check which reduces the amount of checks done and slightly increase the algorithm speed and efficiency.

I was able to compile and run locally a 10x10x10 reactor that does not have the issue anymore.

Fixes #5

[SpaceCat-Chan]

i'm playing nomifactory, and i've tested, it is possible to have two different active coolers touching each other without issue, both of them cool the reactor and can be filled up from outside the reactor, so please add some sort of toggle for this