Use the latest published dataset revision when returning results for the datastore query endpoint

[jastraat]

Use the latest published dataset revision when returning results for the datastore query endpoint.
Also does some slight cleanup of the DatasetBTB test.

To recreate the error in a vanilla DKAN site:

• Create a published dataset with a distribution.

• Set the default moderation state to "draft".

• Edit the dataset and replace the distribution file with data that is recognizably different than the published version. Save as a draft.

• Run cron to do the imports

• Visit the dataset page in the site and confirm that the published version of the dataset is still displayed.

• Use the datastore query endpoint {domain}/api/1/datastore/query/{dataset}/{index} and observe that the data returned is from the unpublished draft, not the published version.

• Test coverage exists

• Documentation exists

QA Steps

• Create a published dataset with a distribution.
• Set the default moderation state to "draft".
• Edit the dataset and replace the distribution file with data that is recognizably different than the published version. Save as a draft.
• Run cron to do the imports
• Verify that the draft revision exists by running ddev drush dkan:dataset-info {datasetID}
• Visit the dataset page in the site and confirm that the published version of the dataset is still displayed.
• Use the datastore query endpoint {domain}/api/1/datastore/query/{dataset}/{index} and observe that the data returned is still from the published version.