Refactor mapping UI
refactor prior to adapting the UI for the mapping editor
(from redmine: issue id 373, created on 2018-01-22tgradl, closed on 2018-01-22)
refactor prior to adapting the UI for the mapping editor
(from redmine: issue id 373, created on 2018-01-22tgradl, closed on 2018-01-22)