Possible memory leak in AwtPanelsContext#createPanel()

There might be a possible memory leak in AwtPanelsContext#createPanel() which automatically adds all created panels to the internal panels list.

An application that might use one or multiple such panels and frequently either creates new panels or disposes previously created panels will cause AwtPanelsContext to hold references to otherwise unused instances. This also includes the attached view ports and and their inherent data such as scene spatials and so on. And, since the user cannot remove the panels from that list, the list will grow over time.

While AwtPanelsContext might only be used with the SDK, I would like to propose that a disposePanel(Panel panel) method be introduced in AwtPanelsContext, so that the caller may free the panels from the context.

In addition I would propose that a detachFrom(ViewPort ... viewports) method be introduced in AwtPanel so that one can dispose of view ports from instances of that panel when needed. I do not know how to handle the attachAsMain use case in that detachFrom(...) method, though, which can be set using the attachTo(...) method.

As attachTo also detaches the existing view ports, the above proposal is void.