'length' used to compare list size with the constant

Something like this `length xs > 5` can be rewritten to handle infinite lists. This can be a separate inspection, or improved suggestion to the existing Infinite length inspection, if we can support such extensible inspections somehow.

Start by reviewing the existing Infinite length inspection and how inspections are extended. Determine whether comparisons such as `length xs > 5` should use a separate inspection or an extensible version of the existing one. Done means the chosen inspection recognizes constant-size comparisons and handles infinite lists safely.

Written by the indexing model from the issue text.