[llvm] [nfc][ctx_prof] Rename `PGOContextualProfile` to `PGOCtxProfContext` (PR #102209)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

Minor comments.

Not too familiar with this area of the code, but given it's a mechanical renaming, it should be fine.

https://github.com/llvm/llvm-project/pull/102209