[clang-tools-extra] [clang-tidy][NFC] Add helper for deprecated check aliases (PR #189522)

[Yanzuo Liu via cfe-commits]

zwuis wrote:

Generally looks good, but I'm not familiar with this part of code.

> Example:
> 
> ```c++
>   if (isDeprecatedAlias("performance-prefer-single-char-overloads")) {
>     diag(Literal->getBeginLoc(),
>          "performance-faster-string-find is deprecated and will be removed in "
>          "a future release; consider using "
>          "performance-prefer-single-char-overloads",
>          DiagnosticIDs::Note);
>   }
> ```

It would be better to call `configurationDiag` instead of `diag`.

https://github.com/llvm/llvm-project/pull/189522