ref #8238 Remove too specific generics from TermTree and TermNode
ref #6794 adapt TaxEditor to new term structure (rename FeatureNode and FeatureTree)
ref #8162 move FeatureTree and FeatureNode to new term package in TaxEditor
ref #6805 Fix term dragging into feature tree editor
ref #6805 Remove e3 drag and drop adapters
ref #6694 Fix session handling when moving feature nodes
ref #6694 Extract composite and Listeners from FeatureTreeEditor