"Did you mean 'get'/'set'?" errors have issues

[DanielRosenwasser]

Follow-up from #26098 (PR at #26446)

Current logic:

• Doesn't ever suggest the identifier/property access in the message (this was requested)
• Only works when the arity of a set is 1 (means it actually doesn't work with Maps)
• Only works when the parameter type's string representation is string.

Each of these is a bug.