fcl-db: mssql: small extending (like in others sqldb/sonnections) schema information returned using SetSchemaInfo call. System tables and functions used should be compatible with MS SQL and also with Sybase.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@23789 3ad0048d-3df7-0310-abae-a5850022a9f2