Fix crash when popping out a layout with tone mapping enabled.

When popping out the layout, the render window releases its ressources,
and the shader cache is deleted. Any used FXAA filter should also releases
there internal ressources.

It wasn't done by the FXAA pass used by tone mapping, leaving the vtkOpenGLQuadHelper
used by vtkOpenGLFXAAFilter in a dirty state, leading to a crash du to invalid pointer
(this->Program).