Fix tooltip & popup positioning (#4740)

* Fix tooltip & popup positioning

This tries to ensure the tooltip & popups are created on the correct
monitor

* Add changelog entry

* Clean up debug output

* Use the full frame geometry to figure out screen bound movements

* Remove the now-unused `setStayInScreenRect` function

* Change the UserInfoPopup offset to be based on its width & height
instead

* Remove more debug output

src/controllers/commands/CommandController.cpp

@@ -923,7 +923,8 @@ void CommandController::initialize(Settings &, Paths &paths)
             static_cast<QWidget *>(&(getApp()->windows->getMainWindow())),
             currentSplit);
         userPopup->setData(userName, channel);
-        userPopup->move(QCursor::pos());
+        userPopup->moveTo(QCursor::pos(), false,
+                          BaseWindow::BoundsChecker::CursorPosition);
         userPopup->show();
         return "";
     });