feat: BaseScript class that loads scheme parameter from json

[kkedziak-splunk]

Solution inspired by this.

This class by default looks for a json file next to the subclass, in order to get scheme parameters.

For example if we have a subclass ExampleInput in example_input.py, it will try to take parameters from example_input.args.json. Of course get_scheme can be overriden.

The json file will be generated by UCC based on globalConfig.json.