Fix: some type hints (tools/extractor, legacy patch stubs) (#285)

* fix tools.extractor type hints

* classes.generated - add legacy patch type hints

* Creating type stubs for legacy patches

This is better than putting all patched classes into __init__.pyi, and may be worth it given the backwards-compatible immutability of the legacy patch.

* better legacy patch stub style

* Remove meaningless stub definitions for legacy patches.