inline TypedDict support

pyright used to support defining TypedDicts inline, like so:

foo: dict[{"foo": int, "bar": str}] = {"foo": "a", "bar": 1}

this was an experimental feature and was removed because it never made it into a PEP. but this functionality is very convenient and we see no reason not to continue supporting it, so we added it back in basedpyright.

this can be disabled by setting enableExperimentalFeatures to false.