Remove automatic creation of DB/collection

Some of the tenanted storage providers will automatically create a container on first use. While this can be convenient—it avoids the need for additional deployment time work—it seems to be more trouble than it's worth. It causes these problems:

* there are one-time failure modes that are a pain to debug, and which often result in manually fixing things up until they work, leading to a lack of repeatabilty (and thus the exact same failure the next time a new environment gets created)
* it can result in us granting inappropriately powerful privileges to the credentials whose main job is just to perform ordinary data access
* it provides poor visibility regarding what resources actually get created during environment creation, and how they are configured
* it can make it non-obvious how the owner of the Azure sub is going to control configuration (because things just magically appear with settings from the guts of our config, rather than going through the normal routes)