Substructure match: add parameter to limit tautomer chain search only by matched struct

[AliaksandrDziarkach]

Current tautomer substructure match realization search tautomer chain starting from any atom of matched struct and check all target molecules atoms.
This is exponential complexity and for large target molecules cause very long time to match.

Decided to add parameter "INNER" and when this parameter added to "TAU" - search tautomer chain only inside matched substructure.