Fix outdated `verification_mode` values
~I think it makes sense not to save `dataset_info.json` file to a dataset cache directory when loading dataset with `verification_mode="no_checks"` because otherwise when next time the dataset is loaded **without** `verification_mode="no_checks"`, it will be loaded successfully, despite some values in info might not correspond to the ones in the repo which was the reason for using `verification_mode="no_checks"` first.~

Updated values of `verification_mode` to the current ones in some places ("none" -> "no_checks", "all" -> "all_checks")