fix(app): many colors fixes in `Linphone.Styles`

tests/ui/modules/Linphone/Colors.qml

@@ -25,4 +25,8 @@ QtObject {
 
   property color o: '#232323' // TextButtonA Hovered.
   property color p: '#B1B1B1' // TextButtonB text Hovered.
+
+  property color q: '#E6E6E6'
+
+  property color r: '#8F8F8F'
 }

tests/ui/modules/Linphone/Styles/CollapseStyle.qml

@@ -6,7 +6,7 @@ QtObject {
   property int iconSize: 32
 
   property Rectangle background: Rectangle {
-    // Do not use Constants.colors.
+    // Do not use `Colors` singleton.
     // Collapse uses an icon without background color.
     color: 'transparent'
   }

tests/ui/modules/Linphone/Styles/Contact/AvatarStyle.qml

 pragma Singleton
 import QtQuick 2.7
 
+import Linphone 1.0
+
 QtObject {
   property QtObject initials: QtObject {
-    property color color: '#FFFFFF'
+    property color color: Colors.k
 
     property int fontSize: 10
   }
 
   property QtObject mask: QtObject {
-    property color color: '#8F8F8F'
+    property color color: Colors.r
 
     property int radius: 50
   }

tests/ui/modules/Linphone/Styles/Contact/ContactDescriptionStyle.qml

 pragma Singleton
 import QtQuick 2.7
 
+import Linphone 1.0
+
 QtObject {
   property QtObject sipAddress: QtObject {
-    property color color: '#5A585B'
+    property color color: Colors.d
 
     property int fontSize: 10
   }
 
   property QtObject username: QtObject {
-    property color color: '#5A585B'
+    property color color: Colors.d
 
     property int fontSize: 11
   }

tests/ui/modules/Linphone/Styles/Form/ListFormStyle.qml

@@ -8,12 +8,12 @@ QtObject {
 
   property QtObject value: QtObject {
     property QtObject backgroundColor: QtObject {
-      property color focused: '#E6E6E6'
+      property color focused: Colors.q
       property color normal: 'transparent'
     }
 
     property QtObject placeholder: QtObject {
-      property color color: '#5A585B'
+      property color color: Colors.d
 
       property int fontSize: 10
     }
@@ -22,8 +22,8 @@ QtObject {
       property int padding: 10
 
       property QtObject color: QtObject {
-        property color focused: '#000000'
-        property color normal: '#5A585B'
+        property color focused: Colors.l
+        property color normal: Colors.d
       }
     }
   }
@@ -33,7 +33,7 @@ QtObject {
     property int iconSize: 16
 
     property QtObject text: QtObject {
-      property color color: '#000000'
+      property color color: Colors.l
 
       property int fontSize: 10
       property int width: 130

tests/ui/modules/Linphone/Styles/MenuStyle.qml

@@ -14,8 +14,8 @@ QtObject {
     property int spacing: 18
 
     property QtObject color: QtObject {
-      property color normal: Colors.g
       property color hovered: Colors.h
+      property color normal: Colors.g
       property color pressed: Colors.i
       property color selected: Colors.j
     }

tests/ui/modules/Linphone/Styles/PanedStyle.qml

@@ -8,9 +8,9 @@ QtObject {
     property int width: 8
 
     property QtObject color: QtObject {
-      property color hovered: '#707070'
-      property color normal: '#C5C5C5'
-      property color pressed: '#5E5E5E'
+      property color hovered: Colors.h
+      property color normal: Colors.c
+      property color pressed: Colors.b
     }
   }
 }