fix(app): many fixes

tests/ui/components/chat/OutgoingMessage.qml

@@ -4,7 +4,6 @@ import QtQuick.Layouts 1.3
 import 'qrc:/ui/components/image'
 
 Message {
-    Layout.fillWidth: true
     backgroundColor: '#E4E4E4'
     id: message
 

tests/ui/components/collapse/Collapse.qml

 import QtQuick 2.7
 
+import 'qrc:/ui/components/image'
+
 // ===================================================================
 
 Item {
@@ -13,11 +15,10 @@ Item {
         rotate.start()
     }
 
-    Image {
+    Icon {
         anchors.fill: parent
-        fillMode: Image.PreserveAspectFit
         id: backgroundImage
-        source: 'qrc:/imgs/collapse.svg'
+        icon: 'collapse'
 
         MouseArea {
             anchors.fill: parent

tests/ui/components/dialog/DialogPlus.qml

@@ -54,9 +54,8 @@ Window {
 
             Row {
                 anchors.left: (!centeredButtons && parent.left) || undefined
-                anchors.horizontalCenter: parent.horizontalCenter
+                anchors.centerIn: centeredButtons ? parent : undefined
                 anchors.leftMargin: 50
-                anchors.verticalCenter: parent.verticalCenter
                 height: 30
                 id: buttons
                 spacing: 20