Automerge: [VPlan] Add printRecipe, prepare printing metadata in ::print (NFC) (#166244)

Add a new pinrRecipe which handles printing the recipe without common
info like debug info or metadata.

Prepares to print them once, in ::print(), after/in combination with
llvm/llvm-project#165825.

PR: llvm/llvm-project#166244

Author: fhahn