without this change we're eagerly resolving placeholder properties in passed URLs / names. Since this happens at bean definition level it's extremely early e.g. Spring Cloud Contract has not yet registered any placeholders that Feign could try to consume.
with this change we're changing the bean to become lazy initialized and we resolve the placeholder values at runtime - as late as possible.

problems:
- one of the tests uses the factory bean - there's no more factory bean since the instance supplier for the bean registration acts as one.