WME: 3D rendering mode does not support screen size change

[lolbot-iichan]

TESTCASE:

1. Start any Wintermute 2.5D game
2. Press Alt+Enter

EXPECTED RESULT: Screen mode is changed, everything is visible

ACTUAL RESULT: Screen mode is changed, but screen is black. It is black until you exit ScummVM or use Return To Launcher feature.

NOTE:
There is a message:
WARNING: BaseRenderOpenGL3D::onWindowChange not yet implemented!