+ fcl-db/dbase: implemented FindFirst,FindNext,FindPrior,FindLast and associated tests

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24107 3ad0048d-3df7-0310-abae-a5850022a9f2
+ fcl-db/dbase: cosmetic; r24107 fixes Mantis #13017

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24108 3ad0048d-3df7-0310-abae-a5850022a9f2