To avoid confusion with FindAllData:
- findAll is a "feature" to retrieve all resources from the endpoint itself ~ a plain GET
- findAllByHref is retrieves lists of resources in general
The initial idea was to type dataService decorator strictly to BaseDataService.
However, HrefOnlyDataService should not expose methods other than findByHref & findAllByHref, but must still work with LinkService.
To address this we introduce HALDataService: an interface with the minimal requirements for a data service to work with HAL links
- dataService decorator can only decorate a class that implements HALDataService
- services retrieved from DATA_SERVICE_FACTORY should therefore work in LinkService
