[kcms/baloo] Disable list view and add folder button when disabled

Other interactive controls in the KCM are disabled when Baloo itself is
disabled; these should follow that pattern for consistency.

kcms/baloo/package/contents/ui/main.qml

@@ -102,6 +102,8 @@ KCM.SimpleKCM {
             Layout.fillWidth: true
             Layout.fillHeight: true
 
+            enabled: fileSearchEnabled.checked
+
             ListView {
                 id: directoryConfigList
                 clip: true
@@ -117,6 +119,8 @@ KCM.SimpleKCM {
 
             Layout.alignment: Qt.AlignRight
 
+            enabled: fileSearchEnabled.checked
+
             icon.name: "folder-add"
             text: i18n("Add folder configuration...")