Improve focus behavior of TableView

The ListView should get active focus on tab, and we need to set
the focus to true so that it actually proxies the TableView
focus correctly.

Change-Id: I2091c7d4320c52acea75464a8d078232b6c8c29b
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>

src/controls/TableView.qml

@@ -247,6 +247,8 @@ ScrollView {
 
     ListView {
         id: listView
+        focus: true
+        activeFocusOnTab: true
         anchors.topMargin: tableHeader.height
         anchors.fill: parent