Throw on Reference fields

[Androlax2]

• Throw an error when a Field expect a Model and we put a Block and inverse
• Throw an error when there is duplicate Model or Block being referenced in Fields that allow references

For example :

 ERROR: model: TestExhaustiveFields - Failed to build model "TestExhaustiveFields": Failed to create field "links_required": Invalid value for "item_types" in the field configuration. The specified item type ID may not exist or may not be compatible.