fix: hp/encumbrance attribute bars restored

[anthonyronda]

Fixes #453. We've discovered that the wrong Datafield subtype (ObjectField) was being used to define parts of the datamodel (correct subtype: SchemaField). This was apparently not crucial to the overall DataModel definition in terms of how Foundry handled our system's data model until DataModel validation changed in V11. Foundry no longer uses template.json as a general schema for finding the fields being used if there's a datamodel definition, so I believe it could no longer find the fields because we were using ObjectField incorrectly

Anyway here's a screenshot from Foundry while testing this changeset

[anthonyronda]

Note: I'm not sure how to test for this

[wyrmisis]

Do we need to make these changes for monsters, too?

[anthonyronda]

Whoops yep