[FIX, INTERNAL] Masai: overloaded Size<> for SparseString, changed sentinels RankDictionary spec to Naive
[TEST] Masai: updated FMIndex files
Merge branch 'test/masai' into develop

* test/masai:
  [TEST] Masai: updated FMIndex files
  [FIX, INTERNAL] Masai: overloaded Size<> for SparseString, changed sentinels RankDictionary spec to Naive