Roslyn analyzer for J2N read-only collections performance issues

[paulirwin]

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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.