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

[Alexander Kornienko via cfe-commits]

alexfh wrote:

@kadircet is working on a repro for the crash we're seeing. @usx95 is looking at the compilation errors.

https://github.com/llvm/llvm-project/pull/111852