[clang] [clang-tools-extra] [clang][Sema] Respect const-qualification of methods in heuristic results (PR #123551)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

For ease of review, I split the PR into two patches (which I plan to squash):
 * The first patch is mechanical changes to use and propagate `QualType` rather than `Type *` in HeuristicResolver interfaces (both public and internal), where it makes sense.
 * The second patch uses the newly propagated qualifier information to fix the bug, and adds a testcase.

https://github.com/llvm/llvm-project/pull/123551