[clang] [Dependency Scanning] Teach `DependencyScanningTool::getModuleDependencies` to Process a List of Module Names (PR #129915)

[Qiongsi Wu via cfe-commits]

qiongsiwu wrote:

I think this change should be here (in contrast to `swift:next`). But there is no clear use case for the multiple module name case in `clang` at the moment. I am all ears for suggestions. 

Maybe I can/should teach `clang-scan-deps` to use a list of module names?

https://github.com/llvm/llvm-project/pull/129915