unlink Qt OpenGL module after converting from QGLWidget to QOpenGLWidget

[krismz]

If/when we've switched to QOpenGLWidget from QGLWidget (which is deprecated as of Qt 5.4), we need to remove the line qt5_use_modules(QtUtils_Utils OpenGL) from QtUtils/Utils/CMakeLists.txt since QOpenGLWidget is in QtWidgets, and QtOpenGL module will not be needed any longer.

[a-y-khan]

Let's set Qt 5 minimum version to 5.4.