Add externally open image support & file download support && more code

cleanup.

qml/component/AvatarContainer.qml

@@ -0,0 +1,32 @@
+import QtQuick 2.11
+import QtQuick.Controls 2.4
+
+Row {
+    spacing: 6
+
+    ImageStatus {
+        id: avatar
+
+        width: height
+        height: 40
+        round: false
+        visible: !sentByMe && aboveAuthor !== author
+        source: author.avatarUrl != "" ? "image://mxc/" + author.avatarUrl : null
+        displayText: author.displayName
+
+        MouseArea {
+            anchors.fill: parent
+
+            hoverEnabled: true
+            ToolTip.visible: containsMouse
+            ToolTip.text: author.displayName
+        }
+    }
+
+    Rectangle {
+        width: height
+        height: 40
+        color: "transparent"
+        visible: !sentByMe && aboveAuthor === author
+    }
+}