Add "Open externally" to media event context menu

TODO.md

@@ -1,7 +1,6 @@
 # TODO
 
 - Image viewer: 
-    - room avatar change event: test open, open externally, copy url & path
     - open externally in context menu in timeline thumbnail, also button
     - hflickable: support kinetic scrolling disabler 
 

src/gui/Pages/Chat/Timeline/EventDelegate.qml

@@ -170,6 +170,13 @@ HColumnLayout {
             onTriggered: eventList.checkFromLastToHere(model.index)
         }
 
+        HMenuItem {
+            icon.name: "open-externally"
+            text: qsTr("Open externally")
+            visible: Boolean(model.media_url)
+            onTriggered: eventList.openMediaExternally(model)
+        }
+
         HMenuItem {
             icon.name: "copy-local-path"
             text: qsTr("Copy local path")

src/icons/thin/open-externally.svg

@@ -0,0 +1,3 @@
+<svg height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg">
+    <path d="m6 17c2.269-9.881 11-11.667 11-11.667v-3.333l7 6.637-7 6.696v-3.333s-6.17-.171-11 5zm12 .145v2.855h-16v-12h6.598c.768-.787 1.561-1.449 2.339-2h-10.937v16h20v-6.769z"/>
+</svg>