NHeader: use label instead of title (matches NLabel)

Widgets/NHeader.qml

@@ -5,19 +5,17 @@ import qs.Commons
 ColumnLayout {
   id: root
 
-  property string title: ""
+  property string label: ""
   property string description: ""
-  property real bottomMargin: Style.marginL * scaling
 
   spacing: Style.marginXXS * scaling
   Layout.fillWidth: true
 
   NText {
-    text: root.title
+    text: root.label
     font.pointSize: Style.fontSizeXXL * scaling
     font.weight: Style.fontWeightBold
     color: Color.mSecondary
-    Layout.bottomMargin: Style.marginS * scaling
     visible: root.title !== ""
   }
 
@@ -27,7 +25,6 @@ ColumnLayout {
     color: Color.mOnSurfaceVariant
     wrapMode: Text.WordWrap
     Layout.fillWidth: true
-    Layout.bottomMargin: root.bottomMargin
     visible: root.description !== ""
   }
 }