validate: launcher: Print test number on result

With parallel test execution, it will be hard to track which result
relates to which test. Therefore, the test number should be printed
along with the results as well.

Patch 3/4 to implement parallel test execution.

https://bugzilla.gnome.org/show_bug.cgi?id=743063

validate/launcher/baseclasses.py

@@ -826,6 +826,7 @@ class TestsManager(Loggable):
                 break
 
             test = self.tests_wait()
+            self.print_test_num(test)
             res = test.test_end()
             self.reporter.after_test(test)
             if res != Result.PASSED and (self.options.forever or