Review functionality that should be extracted from the typespec suppression tool into core libraries

The typespec-suppression tool provides a lot of functionality that might be useful to ship directly from core typespec libraries. Some examples of potential candidates to add to typespec:
- enumerate suppressions
- identify the declaration scope containing a directive
- read linter disables from config
- ast helpers

Helpers and functions in the typespec-suppression tool should be analyzed and a proposal developed as to what functionality would be useful in typespec directly. typespec suppression code: https://github.com/catalinaperalta/azure-rest-api-specs/tree/4043444489b4d384858c2a7a01e123a957bd08ae/eng/tools/typespec-suppressions

Start by reviewing the helpers and functions in the typespec-suppression tool at the linked commit, including suppression enumeration, declaration-scope lookup, linter-disable configuration handling, and AST helpers. Analyze which capabilities belong in core TypeSpec libraries and document a proposal identifying useful functionality and its intended location.

Written by the indexing model from the issue text.