feat(ui/modules/Linphone/TelKeypad/TelKeypadButton): add a line below each button

linphone-desktop/ui/modules/Linphone/Styles/TelKeypad/TelKeypadStyle.qml

@@ -18,9 +18,18 @@ QtObject {
       property color pressed: Colors.i
     }
 
+    property QtObject line: QtObject {
+      property color color: Colors.l50
+      property int bottomMargin: 4
+      property int height: 2
+      property int leftMargin: 8
+      property int rightMargin: 8
+      property int topMargin: 0
+    }
+
     property QtObject text: QtObject {
       property color color: Colors.d
-      property int fontSize: 10
+      property int fontSize: 11
     }
   }
 }

linphone-desktop/ui/modules/Linphone/TelKeypad/TelKeypadButton.qml

 import QtQuick 2.7
-import QtQuick.Controls 2.0
+import QtQuick.Layouts 1.3
 
 import Linphone.Styles 1.0
 
@@ -16,30 +16,44 @@ Item {
 
   // ---------------------------------------------------------------------------
 
-  Button {
+  Rectangle {
     anchors.fill: parent
-
-    background: Rectangle {
     color: button.color
-    }
 
-    contentItem: Text {
+    ColumnLayout {
+      anchors.fill: parent
+
+      spacing: 0
+
+      Text {
+        Layout.fillHeight: true
+        Layout.fillWidth: true
+
         color: TelKeypadStyle.button.text.color
+        elide: Text.ElideRight
 
         font {
           bold: true
           pointSize: TelKeypadStyle.button.text.fontSize
         }
 
-      elide: Text.ElideRight
         text: button.text
 
         horizontalAlignment: Text.AlignHCenter
         verticalAlignment: Text.AlignVCenter
       }
 
-    hoverEnabled: true
+      Rectangle {
+        Layout.fillWidth: true
+        Layout.preferredHeight: TelKeypadStyle.button.line.height
+
+        Layout.bottomMargin: TelKeypadStyle.button.line.bottomMargin
+        Layout.leftMargin: TelKeypadStyle.button.line.leftMargin
+        Layout.rightMargin: TelKeypadStyle.button.line.rightMargin
+        Layout.topMargin: TelKeypadStyle.button.line.topMargin
 
-    onClicked: button.clicked()
+        color: TelKeypadStyle.button.line.color
+      }
+    }
   }
 }