Improve type mapping inference on collections where no model reference is available

Query like this `ss.Set().Where(c => new[] { 2, 999, 1000 }.Where(_ => DateTime.Now.Hour > 10).Count() == 3)` fails to translate/generate, because of no type mapping on `new[] { 2, 999, 1000 }`. There's nothing to infer from, so we should probably fallback to inferring from the collection's type.