Allow custom log levels to be used in scripts#26

As a ScriptRunner for Jira Cloud User,
I would like to be able to specify other log levels other than just info and warn in my script which are all that is currently supported as the default logging level provided by the plugin is INFO level.
So that I can log out other levels such as trace or debug in my scripts without having to manually set these, as currently logs at these leves do not get logged out unless I manually set them per script.