Added API for changing type ref for function/variable and refactored code in some quickfixes to use it
More quickfixes to use API for setting type ref
Corrected quickfix to correct signature of method with 'override' to:
  - not loose annotations and other stuff
  - not include visibility modifiers into the name and into the code generated
Quickfix to correct signature of method with 'override' to not include 'override' in signature text