Filling out TODO items and refactoring ResponseBuilder + computing/formatting of ProcessedMetrics.
Rename Metric::getColumn to Metric::getMetric and get rid of Metrics\Base.
Documented Metric class and fixed regression in last commit's refactor.
Document ProcessedMetric class.
Refactor and deprecate CalculateEvolutionFilter & document some more classes/methods.
Forgot to add files in previous commit and document two more pieces of code.