Tests: Re-introduced pytest based tests. Fixed them a bit, commented-out otherwise. Application tests only runs with logging test, and PLCOpenEditor tests seem broken.

<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema" URI_location="LOCAL://">
  <TargetType/>
</BeremizRoot>