Revisit guidance regarding .Count and .Length

[amanda-mitchell]

Historically, we've enforced a nitpicky guideline that when .Count and .Length are available, they should be preferred over .Any() or .Count().

We could write an analyzer that enforces this, but the more that I think about it, the more it seems like this guidance is primarily aimed at avoiding multiple enumerations of IEnumerable. (see #32)

Perhaps we should instead have good analyzers for #32 and instead have a guideline that we should always use the most appropriate of

• .Any()
• .Count()
• .CountIsExactly()
• .CountIsAtLeast()

[amanda-mitchell]

If we decide to retain the existing rules, Roslynator has some diagnostics to support them.