Codechecker should verify Behat step deprecation

[ziegenberg]

There are a couple of things we could verify with deprecating behat steps correctly:

• deprecated behat steps should be in a behat steps file with the class name ending in _deprecated
• a deprecated behat steps file should extend behat_deprecated_base
• the deprecated step should call $this->deprecated_message()
• there should be no deprecation annotation on the class or the behat step function

There might be more I didn't think about.