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/PageSettingsServersList.qml

@@ -17,6 +17,13 @@ import "../Components"
 PageType {
     id: root
 
+    defaultActiveFocusItem: focusItem
+
+    Item {
+        id: focusItem
+        KeyNavigation.tab: backButton
+    }
+
     ColumnLayout {
         id: header
 
@@ -27,6 +34,8 @@ PageType {
         anchors.topMargin: 20
 
         BackButtonType {
+            id: backButton
+            KeyNavigation.tab: servers
         }
 
         HeaderType {
@@ -39,6 +48,7 @@ PageType {
     }
 
     FlickableType {
+        id: fl
         anchors.top: header.bottom
         anchors.topMargin: 16
         contentHeight: col.implicitHeight
@@ -59,10 +69,36 @@ PageType {
                 clip: true
                 interactive: false
 
+                activeFocusOnTab: true
+                focus: true
+                Keys.onTabPressed: {
+                    if (currentIndex < servers.count - 1) {
+                        servers.incrementCurrentIndex()
+                    } else {
+                        servers.currentIndex = 0
+                        focusItem.forceActiveFocus()
+                        root.lastItemTabClicked()
+                    }
+
+                    fl.ensureVisible(this.currentItem)
+                }
+
+                onVisibleChanged: {
+                    if (visible) {
+                        currentIndex = 0
+                    }
+                }
+
                 delegate: Item {
                     implicitWidth: servers.width
                     implicitHeight: delegateContent.implicitHeight
 
+                    onFocusChanged: {
+                        if (focus) {
+                            server.rightButton.forceActiveFocus()
+                        }
+                    }
+
                     ColumnLayout {
                         id: delegateContent
 
@@ -75,6 +111,7 @@ PageType {
                             Layout.fillWidth: true
 
                             text: name
+                            parentFlickable: fl
                             descriptionText: {
                                 var servicesNameString = ""
                                 var servicesName = ServersModel.getAllInstalledServicesName(index)