LCL: BiDiMode and FlipChildren fixes for TRadioGroup, TCheckGroup and TCheckListbox, patch by wp, bug 25408

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@43576 4005530d-fff6-0310-9dd1-cebe43e6787f
Tests: added BiDiMode and FlipChildren test by wp, bug 25408

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@43577 4005530d-fff6-0310-9dd1-cebe43e6787f