compiler: modernize exception class parse:
  - use specially implemented type search routine in case of declaration with colon (on E: Exception do)
  - parse nested types in case of declaration without colon (on Exception do)
  + test

fixes issue #0022225

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@25412 3ad0048d-3df7-0310-abae-a5850022a9f2