[clang] [clang] CTAD: use index and depth to retrieve template parameter for TemplateParamsReferencedInTemplateArgumentList (PR #98013)

[Matheus Izvekov via cfe-commits]

https://github.com/mizvekov approved this pull request.

LGTM, sans:
* missing newline at end of test file
* A similar test for template template parameter.

https://github.com/llvm/llvm-project/pull/98013