Message menu now holds a shared pointer to a layout (#1787)

This ensures that the layout will survive for the lifetime of the menu,
     so any of the menu actions can with confidence do things with the
     layout, not having to worry whether it's dead or not.

This means that the user, while having the message menu open, could have
one extra MessageLayout alive. I have ensured that when the menu dies
the reference to the shared pointer dies with it.

src/widgets/helper/ChannelView.cpp

@@ -1570,12 +1570,12 @@ void ChannelView::mouseReleaseEvent(QMouseEvent *event)
     }
 
     // handle the click
-    this->handleMouseClick(event, hoverLayoutElement, layout.get());
+    this->handleMouseClick(event, hoverLayoutElement, layout);
 }
 
 void ChannelView::handleMouseClick(QMouseEvent *event,
                                    const MessageLayoutElement *hoveredElement,
-                                   MessageLayout *layout)
+                                   MessageLayoutPtr layout)
 {
     switch (event->button())
     {
@@ -1593,7 +1593,7 @@ void ChannelView::handleMouseClick(QMouseEvent *event,
             auto &link = hoveredElement->getLink();
             if (!getSettings()->linksDoubleClickOnly)
             {
-                this->handleLinkClick(event, link, layout);
+                this->handleLinkClick(event, link, layout.get());
             }
 
             // Invoke to signal from EmotePopup.
@@ -1631,7 +1631,7 @@ void ChannelView::handleMouseClick(QMouseEvent *event,
             auto &link = hoveredElement->getLink();
             if (!getSettings()->linksDoubleClickOnly)
             {
-                this->handleLinkClick(event, link, layout);
+                this->handleLinkClick(event, link, layout.get());
             }
         }
         break;
@@ -1640,13 +1640,15 @@ void ChannelView::handleMouseClick(QMouseEvent *event,
 }
 
 void ChannelView::addContextMenuItems(
-    const MessageLayoutElement *hoveredElement, MessageLayout *layout)
+    const MessageLayoutElement *hoveredElement, MessageLayoutPtr layout)
 {
     const auto &creator = hoveredElement->getCreator();
     auto creatorFlags = creator.getFlags();
 
-    static QMenu *menu = new QMenu;
-    menu->clear();
+    auto menu = new QMenu;
+    connect(menu, &QMenu::aboutToHide, [menu] {
+        menu->deleteLater();  //
+    });
 
     // Emote actions
     if (creatorFlags.hasAny(