bulk export: add support for _typeFilter so we can limit Patient exports to those w/ active = true

[mcjustin]

I'd like to be able to limit Patient exports to those that have active = true. Rationale: we're using this to mark Patient resources as duplicates and/or deleted - those that should be ignored by systems, generally.

It would be good to have this, but not a huge rush: to date the Patient & QuestionnaireResponse exports to the DAWG haven't been utilizing Patient.active, so I need to give them disclaimers anyways.

If this isn't possible, then I'll just need to let users of the DAWG that they should

https://www.hl7.org/fhir/uv/bulkdata/export.html#_typefilter-experimental-query-parameter

sample query at https://www.hl7.org/fhir/uv/bulkdata/export.html#_typefilter-experimental-query-parameter