* Replace some of the conditional logic with polymorphism, especially
  where there is special case logic for certain types of generators
  within other generators.
  * Replace Equality/Inequality with classes that handle all of the
    special cases.
  * Use different classes for inclusive/exclusive Range literals so that
    they can be serialized to SQL differently.
    * Create Veritas::Literal::Range proxy object w/factory method
    * Create Veritas::Literal::Range::Inclusive
    * Create Veritas::Literal::Range::Exclusive

* Adjust reek and roodi scores down to lower thresholds

* Handle cases where an Inequality/Exclusion predicate is used (or a
  Negation wrapping an Equality/Inclusion) on an *optional* attribute.
  * Add "OR attribute IS NULL" to the statement to ensure cases when
    the value is NULL still matches.