The latest changes to the render window data selection (e.g. {D773}) provide a new concept for selecting data nodes for the render windows (see {T29297}).
As a consequence some `RenderWindow*`-classes needed to be modified, are now obsolete or need to be cleaned even more.
This task should tackle the following:
- `mitkRenderWindowLayerController`, `mitkRenderWindowViewDirectionController` and `mitkRenderWindowLayerUtilities` need to be moved to the Core-module
- it needs to be checked if their intent is clear: currently the main reason why the `RenderWindowLayerController` exists is because it requires a data storage to insert a layer node at a specific position, because surrounding nodes need to be checked and moved as well
- the `RenderWindowLayerUtilities` is a class that simply acts on single data nodes and does not require the data storage or looking at other nodes
- it needs to be checked if the classes were cleaned properly, e.g. check if the base layer does not occur anymore
- after the changes in the mentioned differential the main focus of `RenderWindowLayerController` is to insert a node into a specific layer / move nods to a specific layer, whereas the `RenderWindowLayerUtilities` is concerned with setting / deleting the required renderer-specific properties of a node (which is required to have renderer-specific layer-ordering of nodes)
- the `MitkRenderWindowManagerUI`-module can be removed, if
- we want to remove the `org_mitk_gui_qt_renderwindowmanager`-plugin
- the `QmitkRenderWindowDataStorageTreeModel` and `QmitkRenderWindowContextDataStorageInspector` can be removed