[clang] Revert "Reapply "[Clang][Sema] Refactor collection of multi-level template argument lists (#106585, #111173)" (#111852)" (PR #115159)

[Krystian Stasiowski via cfe-commits]

sdkrystian wrote:

@zyn0217 Sorry, I've not had time to work on this recently. I have a branch ready which _should_ address the issues encountered thus far, but I haven't fully tested it yet. I should have time after the weekend.

https://github.com/llvm/llvm-project/pull/115159