[llvm] [nfc][llvm-profdata]Refactor llvm-profdata show* code, by moving function-scope options to a show_llvmprofdata namespace (PR #71328)

[Mingming Liu via llvm-commits]

minglotus-6 wrote:

I updated the PR to exemplify the change for `show_main` and show options. After the refactor pattern is closer to what it should look like eventually, I could apply it to other static *main functions 

https://github.com/llvm/llvm-project/pull/71328