Track actual path position for path.Path<Params>

[Simn]

This may look a bit excessive but finally deals with annoying issue #7282#9705. Type paths can now also store the actual dot path without the type parameters, which was impossible to determine before.

Edit: I really like how obvious pretty errors make this change:

  1 | class User extends ThisObviouslyDoesntExist<T> {}
-   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^
    | Type not found : ThisObviouslyDoesntExist