Determine if check connection button should be defined in properties or not

The HDFS datastore does not require a check connection but the front end guys do not know this and should not care. But they need to have this information to to display or not a button for checking the datastore before showing the datasets.

The salesforce connection check connection button is in the properties. This needs to be considered.

Resolve the question of whether the check connection button should be part of the properties or done via another means by the web renderer