Added tab navigation functional. (#721)

- Added tab navigation functional.
- In basic types added parentFlickable property, which will help to ensure, that the item is visible within flickable parent during tab navigation.
- Added focus state for some basic types.
- In PageType qml file added lastItemTabClicked function, which will help to focus tab bar buttons when the last tab on the current page clicked.
- Added Focus for back button for all pages and drawers.
- Added scroll on tab for Servers ListView on PageHome.

client/ui/qml/Pages2/PageSetupWizardEasy.qml

@@ -16,6 +16,7 @@ PageType {
     id: root
 
     property bool isEasySetup: true
+    defaultActiveFocusItem: focusItem
 
     SortFilterProxyModel {
         id: proxyContainersModel
@@ -32,6 +33,14 @@ PageType {
         }
     }
 
+    Item {
+        id: focusItem
+        implicitWidth: 1
+        implicitHeight: 54
+
+        KeyNavigation.tab: backButton
+    }
+
     BackButtonType {
         id: backButton
 
@@ -39,6 +48,8 @@ PageType {
         anchors.left: parent.left
         anchors.right: parent.right
         anchors.topMargin: 20
+
+        KeyNavigation.tab: continueButton
     }
 
     FlickableType {
@@ -145,17 +156,14 @@ PageType {
                 }
             }
 
-            Item {
-                implicitWidth: 1
-                implicitHeight: 54
-            }
-
             BasicButtonType {
                 id: continueButton
 
                 implicitWidth: parent.width
 
                 text: qsTr("Continue")
+                KeyNavigation.tab: setupLaterButton
+                parentFlickable: fl
 
                 clickedFunc: function() {
                     if (root.isEasySetup) {
@@ -184,6 +192,9 @@ PageType {
                 textColor: "#D7D8DB"
                 borderWidth: 1
 
+                Keys.onTabPressed: lastItemTabClicked(focusItem)
+                parentFlickable: fl
+
                 visible: {
                     if (PageController.isTriggeredByConnectButton()) {
                         PageController.setTriggeredByConnectButton(false)