[3.11] gh-91162: Support splitting of unpacked arbitrary-length tuple over TypeVar and TypeVarTuple parameters (alt) (GH-93412) (GH-93746)

For example:

  A[T, *Ts][*tuple[int, ...]] -> A[int, *tuple[int, ...]]
  A[*Ts, T][*tuple[int, ...]] -> A[*tuple[int, ...], int]
(cherry picked from commit 3473817106c23eca7341c931453da0341c367e1d)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>