Support larger graphs (N>40)

Example of the problem is Tree Search. Or BAMT graphs (see discussion).

The problem is that Tree search is caught in local minima for graphs with N>20. Small graphs are found without problem in 50-100 iterations, while larger graphs (with N>=30 already almost for sure) can't be found. Optimization is stuck after 100-200 iterations with almost no hope. This situation must be investigated.

I have a hypothesis that current mutation set adds cycles and can't remove them.
Also it would be nice to add specific set of constraints for GraphVerifier suited for trees.

Encountered while doing #60

Plan:
1. [ ] Profile GOLEM

Possibly issue #142 could provide additional information about where GOLEM is slower compared to other evolutionary frameworks.

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Updates:
- @ShikovEgor proposed to substitute NetworkX (hich is Pure Python) with something more performant).
- @SuperSashka brought our attention to the fact, that the objective of finding *Same Graph* can be ill-defined, and that's why evolutionary algorithm **in principle** can't resolve it. Yet we should conduct comparison with other papers with similar synthetic tasks for graph search.
- An investigation into architectural barriers of GOLEM must be considered.