Allow generic filter types

[eugenenelou]

This MR allows creating custom filter type with pydantic to reuse across filter classes, by making the field_name implicit.

like:

IContainsField = Annotated[Optional[str], Field(None, q='__icontains')]

class BookFilterSchema(FilterSchema):
    name: IContainsField

[eugenenelou]

fixed the ruff and mypy errors.