Update `get_op_types' endpoint

Update get_op_types endpoint to accept filter parameter , so operation types could be filtered based on input. So basically it should work similar as autosuggestion for input box on frontend. Filter parameter should accept string, when that parameter is active, it renders new filtered operations, for example, we pass co in filter parameter and it returns all operation types that name starts with co, like comment_operation,convert_operation and so on.