Remove View::minimumSizeHint()

It's a QWidget specific concept, so move it to the qtwidgets
frontendcode. QtQuick won't need it.

src/ViewWrapper.cpp

@@ -31,24 +31,12 @@ void ViewWrapper::setMinimumSize(QSize)
     qFatal("Not implemented");
 }
 
-QSize ViewWrapper::minSize() const
-{
-    qFatal("Not implemented");
-    return {};
-}
-
 QSize ViewWrapper::maxSizeHint() const
 {
     qFatal("Not implemented");
     return {};
 }
 
-QSize ViewWrapper::minimumSizeHint() const
-{
-    qFatal("Not implemented");
-    return {};
-}
-
 QRect ViewWrapper::normalGeometry() const
 {
     qFatal("Not implemented");