[clang-tools-extra] [clang-tidy] Rename 'cert-err34-c' to 'bugprone-unchecked-string-to-number-conversion' (PR #157285)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> The commit message title can be a bit misleading, I read it as "create a new alias in bugprone, which points to the cert check", but in reality the intention is the other way around, alias from bugprone to cert.

Yeah, it was tricky to write. I hope "rename" would be more clear

https://github.com/llvm/llvm-project/pull/157285