[test] Tests for passing persisted resource instances with array/List properties to resource methods expecting Array datatypes
[api] [minor] Append validation errors as string to main error message
[api] [fix] Treat array and object property types as JSON. JugglingDB List type features lazy loading of items from the datasource which is good but not 100% desirable here.
[test] Compare items to Array instead of List
[test] Use Array instead of List