Support mypy ignore annotation with particular rule specified (#51675)
Summary:
Previously TorchScript allows a ignore-all type check suppression rule that looks like
```
code code code # type: ignore
```
But a more common use case is
```
code code code # type: ignore[specific-rule]
```
This PR allows the more common use case
Fixes https://github.com/pytorch/pytorch/issues/48643
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51675
Reviewed By: ansley
Differential Revision: D26304870
Pulled By: gmagogsfm
fbshipit-source-id: 0ac9ee34f0219c86e428318a69484d5aa3ec433f
