### SUMMARY

Update validate-modules to report messages using named error codes like `version-added` instead of error numbers like `E305`.

This would match the behavior of other tools we use, such as pylint, which have one named error code per rule. This will also make ignore entries much easier to read.

Doing this before 2.9 is released will avoid potential backwards compatibility issues with ignore entries in collections.

##### ISSUE TYPE

Feature Idea

##### COMPONENT NAME

validate-modules

path=self.object_path,
                                code=209,
                                msg=('Only the following from __future__ imports are allowed: %s'
                                     % ', '.join(self.WHITELIST_FUTURE_IMPORTS)),
                                line=child.lineno
                            )
                            break
                    else:  
                        continue
                import_lines.append(child.lineno)
                if child.lineno < min_doc_line:
                    self.reporter.error(
                        path=self.object_path,
                        code=106,
                        msg=('Import found before documentation variables. '
                             'All imports must appear below '
                             'DOCUMENTATION/EXAMPLES/RETURN/ANSIBLE_METADATA.'),
                        line=child.lineno
                    )
                    break
            elif isinstance(child, TRY_EXCEPT):
                bodies = child.body
                for handler in child.handlers:
                    bodies.extend(handler.body)
                for grandchild in bodies:
                    if isinstance(grandchild, (ast.Import, ast.ImportFrom)):
                        import_lines.append(grandchild.lineno)
                        if grandchild.lineno < min_doc_line:
                            self.reporter.error(
                                path=self.object_path,