[clang] CTAD: Track template template type parameters that referenced in the...

[clang] CTAD: Track template template type parameters that referenced in the template arguments of the RHS. (#85405)

Fixes https://github.com/llvm/llvm-project/issues/85385.

The Finder was missing for this case, for the crash test, the template
parameter TTP was incorrectly considered as not referenced/appeared in
the template arguments of the right hand side of the alias template
decl, thus the synthesized deduction decl doesn't contain this TTP in
the template parameter list, but we have references in the declaration,
thus it caused crashes.