TypeVarTuple Transformations Before Unpack

It would be useful to be able to apply type transformations to TypeVarTuple's types. Some motivating examples:

 Ts = TypeVarTuple('Ts')

 class Example(Generic[*Ts]):
     def __init__(self, *types: *type[Ts]) -> None:
         self.types = types

     def create_defaults(self) -> tuple[*Ts]:
         return tuple(t() for t in self.types)

     def create_lists(self) -> tuple[*list[Ts]]:
         return tuple([t()] for t in self.types)

     def create_callables(self) -> tuple[*Callable[[], Ts]]:
         return tuple(lambda: t() for t in self.types)

 e = Example(int, str)

 assert_type(e.create_defaults(), tuple[int, str])
 assert_type(e.create_lists(), tuple[list[int], list[str]])
 assert_type(e.create_callables(), tuple[Callable[[], int], Callable[[], str]])

At a high level, everything between the * and the TypeVarTuple it expands would be applied per type in the tuple before it's unpacked.

There are some decisions to be made about how the expansion is done if there are multiple TypeVarTuples in the expand expression, but I think it can be supported and I think the intuitive thing would be to zip up all the TypeVarTuples. For example,
tuple[*tuple[Ts, Us]] with Ts = (int, str) and Us = (float, bytes) would be tuple[tuple[int, float], tuple[str, bytes]], with the implementation enforcing equal-length TypeVarTuples.

If there's a workaround for this using the existing logic, let me know. My current use case involves keeping a reference to the runtime types, so *type[Ts] is what I'm looking for at the moment.

未指定文件、测试或入口点。首先审查现有的 TypeVarTuple 解包行为和动机示例，然后定义转换如何在解包之前应用，包括针对多个 TypeVarTuples 提议的等长度 zip 语义。当该功能的行为以及尚未解决的展开决策都被明确规范到足以实现时，即视为完成。