camel health - Remove HealthCheckRepository and routes check

Lets simplify the health check api and the default implementations.

The routes check is overlapping what monitoring systems can do by checking and reporting on metrics, such as if N errors within last Y minute then YELLOW etc.

This job is better handled by those tools, than Camel.

So the health checks become a basic API that are invoked on demand (ala spring boot acutators).

And then we only need one kind of registry so removing the additional repository layer.