Cache type considerations

[micimize]

For us to have a strongly typed, normalized cache:

• Types must be partials like Partial<ObjectType> in typescript
• Relationships need to be replaced with references, possibly with associated type aware getters. E.g:

Reference<Task> _taskId;
Task get referencedTask => _dereference(_taskId);

This means we definitely need to generate separate models if we want a strongly typed cache.