States editor is not destroying state editor tabs proper and those child controller and widgets

[franzlst]

The states editor should destroy respective state editor widget of removed states recursively in a proper way. At the moment the widgets are maybe hidden or in no list but still active. Issue #228 is an example for it. The problem is maybe solved if respective widgets get refactored.

The issue includes tree sub-tasks

• fix the states editor to remove and destroy all state editor widget in a proper way
• check to refactor the transitions, data flow widget to use ExtendedController destroy method
• verify and conserve the functionality by a unit-test that could be similar to the destruct test used for issue Full support for Core and GUI elements destruction #246 (maybe reuse and modify the class patching methods of it).

Originally created by @Rbelder at 2016-11-17 15:07:02+00:00 (moved from RMC internal repository)

[franzlst]

So the issue actually has started because the outcomes-, transitions- and data flow-list controller are not destroyed clean and maybe also not fully. This issue should start a good measurement of the destruction of the widgets involved in the state editor and the states editor tabs.
I also added a sub-task in the first comment.

Originally created by @Rbelder at 2016-11-17 17:17:04+00:00 (moved from RMC internal repository)