Add basic cross-signing support

src/qml/AccountMenu.qml

@@ -71,6 +71,12 @@ QQC2.Menu {
             title: i18nc("@title:window", "Open Key Backup")
         })
     }
+    QQC2.MenuItem {
+        text: i18nc("@action:inmenu", "Verify this Device")
+        icon.name: "security-low"
+        onTriggered: root.connection.startSelfVerification()
+        enabled: Controller.ssssSupported
+    }
     QQC2.MenuItem {
         text: i18n("Logout")
         icon.name: "list-remove-user"

src/qml/DirectChatDrawerHeader.qml

@@ -59,12 +59,27 @@ ColumnLayout {
         }
     }
 
-    Kirigami.Heading {
+    RowLayout {
         Layout.fillWidth: true
-        type: Kirigami.Heading.Type.Primary
-        wrapMode: QQC2.Label.Wrap
-        text: root.room.displayName
-        textFormat: Text.PlainText
-        horizontalAlignment: Text.AlignHCenter
+        Layout.alignment: Qt.AlignHCenter
+        Kirigami.Icon {
+            id: securityIcon
+            //TODO figure out how to make this update
+            source: room.connection.isUserVerified(root.room.directChatRemoteMember.id) ?
+                        (room.connection.allSessionsSelfVerified(root.room.directChatRemoteMember.id) ? "security-high" : "security-medium")
+                        : "security-low"
+
+        }
+        Kirigami.Heading {
+            type: Kirigami.Heading.Type.Primary
+            wrapMode: QQC2.Label.Wrap
+            text: root.room.displayName
+            textFormat: Text.PlainText
+            horizontalAlignment: Text.AlignHCenter
+        }
+        Item {
+            Layout.preferredWidth: visible ? securityIcon.width : 0
+            visible: securityIcon.visible
+        }
     }
 }

src/qml/RoomInformation.qml

@@ -89,6 +89,16 @@ QQC2.ScrollView {
                 }
             }
 
+            Delegates.RoundedItemDelegate {
+                visible: root.room.isDirectChat()
+                icon.name: "security-low-symbolic"
+                text: i18nc("@action:button", "Verify user")
+
+                onClicked: root.room.startVerification()
+
+                Layout.fillWidth: true
+            }
+
             Delegates.RoundedItemDelegate {
                 id: favouriteButton
                 visible: !root.room.isSpace