qml: add first qml testcase

Author: Johnny Carlson

src/qml/test/tst_onboarding.qml

@@ -0,0 +1,24 @@
+import "../controls"
+import "../controls"
+import "../pages/onboarding"
+import QtQuick 2.15
+import QtTest 1.15
+
+Rectangle {
+    id: root
+    width: 640
+    height: 665
+    color: Theme.color.background
+
+    OnboardingCover {}
+
+    TestCase {
+        id: onboardingFlow
+        when: windowShown
+        
+        function test_maths() {
+            var image = grabImage(root)
+            image.save("./output.png")
+        }
+    }
+}