Move the Decorator, ThreadNameWithParenthesis, and DescribeThread to asan_descriptions.{h,cc}

Summary:
Replacement for part of D23518
Code refactoring to allow us to move some more DescribeAddressIf* functions to work by getting the structured information, and then printing it.

Reviewers: kcc, samsonov

Subscribers: kubabrecka, llvm-commits

Differential Revision: https://reviews.llvm.org/D23520

llvm-svn: 278820