Convert to Sibling Refactoring does not work with namespace qualified class names

[blairmcg]

Attempting to perform a Convert to Sibling refactoring has a couple of issues:

1. The dialog trims off the namespace prefix from the abstract class name it proposes, which would define the class in Smalltalk rather than the original namespace (although this does at least work)
2. If the namespace prefix is edited back in, when OK is pressed the refactoring fails:

   27/06/2021 17:19:51: 'UndefinedObject does not understand #compile:classified:'
   Core.Object>>doesNotUnderstand:
   ChildrenToSiblingsRefactoring>>pushUp:in:
   [] in ChildrenToSiblingsRefactoring>>pushUpMethodsFrom:
   Set>>do:
   ChildrenToSiblingsRefactoring>>pushUpMethodsFrom:
   ChildrenToSiblingsRefactoring>>pushUpMethods
   ChildrenToSiblingsRefactoring>>transform
   ChildrenToSiblingsRefactoring(Refactoring)>>primitiveExecute
   ChildrenToSiblingsRefactoring(Refactoring)>>execute
   [] in Tools.RefactoringSmalltalkSystem>>convertToSibling:
   ExceptionHandlerSet(ExceptionHandlerAbstract)>>markAndTry
   [] in ExceptionHandlerSet(ExceptionHandlerAbstract)>>try:
   BlockClosure>>ensure:
   ExceptionHandlerSet(ExceptionHandlerAbstract)>>try:
   BlockClosure>>on:do:on:do:
   RefactoringSmalltalkSystem>>handleRefactoringException:
   RefactoringSmalltalkSystem>>convertToSibling:
   ClassHierarchySelector(ClassSelector)>>convertToSibling
   Symbol>>forwardTo:
   CommandDescription>>performAgainst:
   [] in Command>>value
   BlockClosure>>ensure:
   Command>>value
   ShellView>>performCommand:
   ClassBrowserShell(Shell)>>performCommand:
   CommandQuery>>perform
   DelegatingCommandPolicy(CommandPolicy)>>route:
   [] in TreeView(View)>>onCommand:
   BlockClosure>>ensure:
   Cursor>>showWhile:
   TreeView(View)>>onCommand:
   TreeView(View)>>wmCommand:wParam:lParam:
   TreeView(View)>>dispatchMessage:wParam:lParam:
   [] in Kernel.InputState>>wndProc:message:wParam:lParam:cookie:
   BlockClosure>>ifCurtailed:
   GuiInputState(InputState)>>wndProc:message:wParam:lParam:cookie:
   GuiInputState(InputState)>>pumpMessage:
   GuiInputState(InputState)>>loopWhile:
   GuiInputState(InputState)>>mainLoop
   [] in GuiInputState(InputState)>>forkMain
   ExceptionHandler(ExceptionHandlerAbstract)>>markAndTry
   [] in ExceptionHandler(ExceptionHandlerAbstract)>>try:
   BlockClosure>>ensure:
   ExceptionHandler(ExceptionHandlerAbstract)>>try:
   BlockClosure>>on:do:
   [] in BlockClosure>>newProcess:

[blairmcg]

Fixed by ecc4c9ea