Typing-inspection

- Add support for `dataclasses.InitVar` as a type qualifier by Viicos in [31](https://github.com/pydantic/typing-inspection/pull/31)
A new `DATACLASS` annotation source is added.
- Add explicit annotation for `ForbiddenQualifier` exception by Viicos in [30](https://github.com/pydantic/typing-inspection/pull/30)

- Allow unhashable items in `Literal` forms by Viicos in [28](https://github.com/pydantic/typing-inspection/pull/28)

- Handle bare `ClassVar` type qualifiers, rename `INFERRED` sentinel by Viicos in [26](https://github.com/pydantic/typing-inspection/pull/26)
While currently not explicitly allowed by the typing specification, `ClassVar` is allowed as a bare type qualifier.
Unlike `Final`, the actual type doesn't have to be inferred from the assignment (e.g. one can use `Any`).
For this reason, the `INFERRED` sentinel was renamed to `UNKNOWN`.

- Add `typing_objects.is_deprecated()` by Viicos in [24](https://github.com/pydantic/typing-inspection/pull/24)
- Add missing positional only parameter markers in `typing_objects` stub file by Viicos in [23](https://github.com/pydantic/typing-inspection/pull/23)
- Add project URLs by Viicos in [22](https://github.com/pydantic/typing-inspection/pull/22)

Initial release.