[Analyzer][StreamChecker] Use BugType instead of BuiltinBug (NFC) .

Summary:
I do not like the BuiltinBug class.
And it takes no SuppressOnSink parameter that may be needed in the future.

Reviewers: Szelethus, baloghadamsoftware, gamesh411

Reviewed By: Szelethus

Subscribers: rnkovacs, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, gamesh411, Charusso, martong, ASDenysPetrov, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82741