Bound the suggested floating window geometry

Because why not, seems correct. No bug would happen with QtWidgets
since QtWidgets respect the min sizes of their children, but for
QtQuick it's more flaky as there's no intrinsic mechanism for
min sizes, so give it some help

src/controllers/DockWidget.cpp

@@ -540,6 +540,7 @@ Controllers::FloatingWindow *DockWidget::Private::morphIntoFloatingWindow()
         auto frame = new Controllers::Frame();
         frame->addWidget(q);
         geo.setSize(geo.size().boundedTo(frame->view()->maxSizeHint()));
+        geo.setSize(geo.size().expandedTo(frame->view()->minSize()));
         Controllers::FloatingWindow::ensureRectIsOnScreen(geo);
         auto floatingWindow = new Controllers::FloatingWindow(frame, geo);
         floatingWindow->view()->show();