introducing merge_body_with_updates flag support in common/import, setting to true in statistics workflow
removing common import input parameters which are not required in this context
introducing trust_level_threshold support in statistics workflow
introducing dedicated statistics mainworkflow encapsulating importing, processing and exporting phases. This workflow was introduced explicitly for statistics purposes because we want to operate over InformationSpace imported data in contrary to primary workflow where some of the statistics input was inferred and it wasn't clear whether it will become part of InformationSpace.