move string indexes to separate namespace

...src/stringology/indexing/BitParallelIndexConstruction.cpp

...o/src/stringology/indexing/BitParallelIndexConstruction.h

...ology/indexing/CompressedBitParallelIndexConstruction.cpp

...ngology/indexing/CompressedBitParallelIndexConstruction.h

alib2algo/src/stringology/indexing/PositionHeapNaive.cpp

alib2algo/src/stringology/indexing/PositionHeapNaive.h

alib2algo/src/stringology/indexing/SuffixArrayNaive.cpp

alib2algo/src/stringology/indexing/SuffixArrayNaive.h

alib2algo/src/stringology/indexing/SuffixTrieNaive.cpp

alib2algo/src/stringology/indexing/SuffixTrieNaive.h

alib2algo/src/stringology/query/BitParallelismFactors.cpp

alib2algo/src/stringology/query/BitParallelismFactors.h

...src/stringology/query/CompressedBitParallelismFactors.cpp

...o/src/stringology/query/CompressedBitParallelismFactors.h

alib2algo/src/stringology/query/PositionHeapFactors.cpp

alib2algo/src/stringology/query/PositionHeapFactors.h

alib2algo/src/stringology/query/SuffixArrayFactors.cpp

alib2algo/src/stringology/query/SuffixArrayFactors.h

alib2algo/src/stringology/query/SuffixTrieFactors.cpp

alib2algo/src/stringology/query/SuffixTrieFactors.h