This change is meant to allowing user params to take precedence over hive params. Currently, it's the other way around.

Particularly, if you have the situation where you have a large number of users who use an authentication method other than the default basic, but your service account (AGG_SERVICE_ACCOUNT) is using basic then you need to specify a user param for each of your users.

With this change, you can set default authentication params in pm_hive_params for all users, and then set your service account specifically to be authentication_method = 'BASIC'. May seem like a small change, but it would be very welcome not to need to assign params for each new user at our institution.

In the process of making this change, I re-organized basic authentication into its own package and removed some code duplication.