make it work (only) with Devel::StackTrace 2.00

I have reworked the code to pass tests against D::ST 2.00

I have also imported all the D::ST tests, to make sure that D::ST::WL is completely compatible. I have added lexicals-related checks into those, because the logic to figure out the argument to peek_my needed checking in case of frame filters and frame skips.

All tests pass. This should close RT# 100278 and RT# 99957