Roslyn analyzer for J2N read-only collections performance issues

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Task description

Split from #928.

Originally posted by @NightOwl888:
> It would probably also be sensible to add warnings to our Roslyn code analyzer to warn users that there may be a performance downgrade if they use a BCL collection type in cases where there would be a performance downgrade. This only happens when comparing collection equality or formatting the contents of the collection, IIRC.

See #984 for more context.

Start by reading the context in #928 and #984, then inspect the existing Roslyn analyzer entry points. Determine which BCL collection uses in collection equality or content formatting should produce a performance warning, and define the warning scope and validation cases before implementing it.

Written by the indexing model from the issue text.