feat: implement legacy field, resource and collection decorators for supporting @ember-data/model migration

[runspired]

In order to enable a granular migration

• field replaces attr and moves serialize/deserialize logic to the new location
• resource replaces belongsTo and exposes a RelationshipDocument, no more async promises
• collection replaces hasMany and exposes a RelationshipDocument, no more async promises

Constraints will be

• these decorators do not work with classic ember syntax (e.g. Model.extend({ name: attr() }))
• therefore these decorators do not work in mixins
• probably some more things as we figure out how to interop with computed correctly

Implementation will be achieved by

• the decorators will at install time pad additional information somewhere we can retrieve it. Existing schema extraction paths will be updated to pull from this information.
• we will have to figure out how to make this work without instantiating a record class first