[clang][extract-api] Suppprt for the module name property in SymbolGraph

Adds `--product-name=` flag to the clang driver. This gets forwarded to
cc1 only when we are performing a ExtractAPI Action. This is used to
populate the `name` field of the module object in the generated SymbolGraph.

Differential Revision: https://reviews.llvm.org/D122141