[clang] [clang][analyzer] Add plist macro formatting (PR #156046)

[Balázs Benics via cfe-commits]

steakhal wrote:

I think we should discuss an earlier comment of mine:

> I don't see why plist are treated differently. Through that lens, I don't see the justification for this option.
IMO we should just always return the formatted macros for all diagnostic consumers - including but not limited to the plist generator.
Maybe provide an escape hatch in the unforeseen case that clang-format would crash on something.

Fundamentally, the question is why should we have two separate APIs for getting the expanded text?
One that was already used, and another for this new formatted text. Why don't we just expose the latter?

https://github.com/llvm/llvm-project/pull/156046