Nsparse for cfpq

- [ ] Implement [cfpq](https://github.com/YaccConstructor/articles/blob/master/2018/GRADES-NDA/Rustam_matrices/graphparsing.pdf) by using [nsparse](https://github.com/EBD-CREST/nsparse) library. Use set-of-nonterminal representation of matrices cells. So, first of all, you should to modify multiplication operation in nsparse library.
- [ ] Evaluate and compare with other implementations.