feat(dfa): #43 add dfa minimization algorithm

Implement the minimize function for the DFA class. This funciton is used to reduce the number of redundant states in the DFA.
Add test cases for the minimize function.
Fix a bug in the accepts function of the DFA class where the empty string was being accepted by the DFA even when it was not in a final state.
Modify some existing functions to make them private and add type hints to the functions.
Modify the minimize function in the NFA class to use the minimize function of the DFA class when converting the NFA to a DFA.

rohaquinlop / automathon