New window for file filter property editor. Earlier one was generated in code.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42761 4005530d-fff6-0310-9dd1-cebe43e6787f
PropEdits: Use a proper designer form for file filter property editor and add up/down buttons. Issue #24811

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42762 4005530d-fff6-0310-9dd1-cebe43e6787f