[clang-tools-extra] [clang-tidy] [NFC] Move comment scanning to `LexerUtils` and add tests (PR #180371)

[Victor Chernyakin via cfe-commits]

================
@@ -17,6 +17,8 @@
 using namespace clang::ast_matchers;
 
 namespace clang::tidy::bugprone {
+
+using clang::tidy::utils::lexer::CommentToken;
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localspook wrote:

Does this work?
```suggestion
using utils::lexer::CommentToken;
```

https://github.com/llvm/llvm-project/pull/180371