Moving/adding checks for options to train_config configuration

Summary

This MR introduces the following changes

• Moving check for working_point and n_jets to train_config configuration for validation/evaluation with a freshly trained tagger.
• Adding check for frac_values to train_config configuration for validation/evaluation with a freshly trained tagger.
• Adding checks for tagger and frac_values_comp to the train_config configuration for the validation/evaluation without a freshly trained tagger.
• Removing unused checks in various places for the moved/added checks.
• Adding unit tests for the configuration for the new checks

Relates to the following issues

• Closing #208 (closed)

Conformity

• Changelog entry
• Documentation
• Development guidelines
• Style guides