redesign string parser registration

alib2str/src/alphabet/string/BarSymbol.cpp

alib2str/src/alphabet/string/BlankSymbol.cpp

alib2str/src/alphabet/string/BottomOfTheStackSymbol.cpp

alib2str/src/alphabet/string/EndSymbol.cpp

alib2str/src/alphabet/string/InitialSymbol.cpp

alib2str/src/alphabet/string/NonlinearVariableSymbol.cpp

alib2str/src/alphabet/string/RankedSymbol.cpp

alib2str/src/alphabet/string/StartSymbol.cpp

alib2str/src/alphabet/string/VariablesBarSymbol.cpp

alib2str/src/alphabet/string/WildcardSymbol.cpp

alib2str/src/automaton/string/FSM/DFA.cpp

alib2str/src/automaton/string/FSM/EpsilonNFA.cpp

alib2str/src/automaton/string/FSM/EpsilonNFA.h

alib2str/src/automaton/string/FSM/MultiInitialStateNFA.cpp

alib2str/src/automaton/string/FSM/MultiInitialStateNFA.h

alib2str/src/automaton/string/FSM/NFA.cpp

alib2str/src/container/string/ObjectsPair.cpp

alib2str/src/container/string/ObjectsSet.cpp

alib2str/src/container/string/ObjectsVector.cpp

alib2str/src/grammar/string/ContextFree/CFG.cpp