Represent finite types as union of literals for checking overloads

[sterliakov]

May close #14764. Not even close to completion, I just want to see mypy-primer output now

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

pandas (https://github.com/pandas-dev/pandas)
+ pandas/core/tools/numeric.py:215: error: Unused "type: ignore" comment  [unused-ignore]
+ pandas/io/parsers/base_parser.py:640: error: Unused "type: ignore" comment  [unused-ignore]
+ pandas/io/parsers/base_parser.py:657: error: Argument 1 to "IntegerArray" has incompatible type "ExtensionArray | ndarray[Any, Any]"; expected "ndarray[Any, Any]"  [arg-type]
+ pandas/io/parsers/base_parser.py:659: error: Argument 1 to "BooleanArray" has incompatible type "ExtensionArray | ndarray[Any, Any]"; expected "ndarray[Any, Any]"  [arg-type]
+ pandas/io/parsers/base_parser.py:661: error: Argument 1 to "FloatingArray" has incompatible type "ExtensionArray | ndarray[Any, Any]"; expected "ndarray[Any, Any]"  [arg-type]
+ pandas/io/parsers/base_parser.py:676: error: Unused "type: ignore" comment  [unused-ignore]
+ pandas/io/parsers/base_parser.py:681: error: Argument 1 to "BooleanArray" has incompatible type "ExtensionArray | ndarray[Any, Any]"; expected "ndarray[Any, Any]"  [arg-type]
+ pandas/io/parsers/base_parser.py:684: error: Argument 1 to "is_datetime_array" has incompatible type "ExtensionArray | ndarray[Any, Any]"; expected "ndarray[Any, Any]"  [arg-type]

mongo-python-driver (https://github.com/mongodb/mongo-python-driver)
+ pymongo/asynchronous/database.py:906: error: Not all union combinations were tried because there are too many unions  [misc]

streamlit (https://github.com/streamlit/streamlit)
- lib/tests/streamlit/elements/file_uploader_test.py:106:26: error: No overload variant matches argument types "str", "str", "bool"  [call-overload]
- lib/tests/streamlit/elements/file_uploader_test.py:106:26: note: Possible overload variants:
- lib/tests/streamlit/elements/file_uploader_test.py:106:26: note:     def file_uploader(self, label: str, type: Union[str, Sequence[str], None], accept_multiple_files: Literal[True], key: Optional[Union[str, int]] = ..., help: Optional[str] = ..., on_change: Optional[Callable[..., None]] = ..., args: Optional[Tuple[Any, ...]] = ..., kwargs: Optional[Dict[str, Any]] = ..., *, disabled: bool = ..., label_visibility: Literal['visible', 'hidden', 'collapsed'] = ...) -> Optional[List[UploadedFile]]
- lib/tests/streamlit/elements/file_uploader_test.py:106:26: note:     def file_uploader(self, label: str, type: Union[str, Sequence[str], None], accept_multiple_files: Literal[False] = ..., key: Optional[Union[str, int]] = ..., help: Optional[str] = ..., on_change: Optional[Callable[..., None]] = ..., args: Optional[Tuple[Any, ...]] = ..., kwargs: Optional[Dict[str, Any]] = ..., *, disabled: bool = ..., label_visibility: Literal['visible', 'hidden', 'collapsed'] = ...) -> Optional[UploadedFile]
- lib/tests/streamlit/elements/file_uploader_test.py:106:26: note:     def file_uploader(self, label: str, *, accept_multiple_files: Literal[True], type: Union[str, Sequence[str], None] = ..., key: Optional[Union[str, int]] = ..., help: Optional[str] = ..., on_change: Optional[Callable[..., None]] = ..., args: Optional[Tuple[Any, ...]] = ..., kwargs: Optional[Dict[str, Any]] = ..., disabled: bool = ..., label_visibility: Literal['visible', 'hidden', 'collapsed'] = ...) -> Optional[List[UploadedFile]]
- lib/tests/streamlit/elements/file_uploader_test.py:106:26: note:     def file_uploader(self, label: str, *, accept_multiple_files: Literal[False] = ..., type: Union[str, Sequence[str], None] = ..., key: Optional[Union[str, int]] = ..., help: Optional[str] = ..., on_change: Optional[Callable[..., None]] = ..., args: Optional[Tuple[Any, ...]] = ..., kwargs: Optional[Dict[str, Any]] = ..., disabled: bool = ..., label_visibility: Literal['visible', 'hidden', 'collapsed'] = ...) -> Optional[UploadedFile]
+ lib/tests/streamlit/elements/file_uploader_test.py:118:45: error: Argument 1 to "zip" has incompatible type "Union[List[UploadedFile], UploadedFile, None]"; expected "Iterable[Iterable[object]]"  [arg-type]
+ lib/tests/streamlit/elements/file_uploader_test.py:119:38: error: "Iterable[object]" has no attribute "name"  [attr-defined]
+ lib/tests/streamlit/elements/file_uploader_test.py:120:38: error: "Iterable[object]" has no attribute "type"  [attr-defined]
+ lib/tests/streamlit/elements/file_uploader_test.py:121:38: error: "Iterable[object]" has no attribute "size"  [attr-defined]
+ lib/tests/streamlit/elements/file_uploader_test.py:122:38: error: "Iterable[object]" has no attribute "getvalue"  [attr-defined]
+ lib/tests/streamlit/elements/file_uploader_test.py:126:34: error: Item "List[UploadedFile]" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "name"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:126:34: error: Item "None" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "name"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:127:34: error: Item "List[UploadedFile]" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "type"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:127:34: error: Item "None" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "type"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:128:34: error: Item "List[UploadedFile]" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "size"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:128:34: error: Item "None" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "size"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:129:34: error: Item "List[UploadedFile]" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "getvalue"  [union-attr]
+ lib/tests/streamlit/elements/file_uploader_test.py:129:34: error: Item "None" of "Union[List[UploadedFile], UploadedFile, None]" has no attribute "getvalue"  [union-attr]

pydantic (https://github.com/pydantic/pydantic)
+ pydantic/v1/dataclasses.py:214: error: Not all union combinations were tried because there are too many unions  [misc]
+ pydantic/dataclasses.py:233: error: Not all union combinations were tried because there are too many unions  [misc]
+ pydantic/dataclasses.py:233: note: Error code "misc" not covered by "type: ignore" comment

hydra-zen (https://github.com/mit-ll-responsible-ai/hydra-zen)
+ src/hydra_zen/structured_configs/_implementations.py:1175: error: Not all union combinations were tried because there are too many unions  [misc]
+ src/hydra_zen/structured_configs/_implementations.py:3684: error: Incompatible return value type (got "Any | Builds[type[_T]]", expected "ZenPartialBuilds[type[_T]] | HydraPartialBuilds[type[_T]]")  [return-value]