Indicate whether a proposed fix is unsafe

For example, this one would break the code (because `is not` cannot be overridden, so for certain SQLAlchemy comparisions, `==`/`!=` comparisons against `None` are required):


Of course I know that it would not be safe to "fix" it, but maybe a less experienced developer might blindly apply the fix instead of adding noqa and then wonder why their code does not work.

Start by reproducing the SQLAlchemy comparison example in the Ruff VS Code extension and reviewing how proposed fixes are presented. Done means the extension clearly indicates when a proposed fix is unsafe, while safe fixes remain available and users can choose an appropriate alternative such as adding noqa.

Written by the indexing model from the issue text.