feat: allow reconcilers to override their own configuration

[metacosm]

Signed-off-by: Chris Laprun [email protected]

[csviri]

What is the use case for this change?

Would be good to document it at least as Javadoc on the interface

[metacosm]

What is the use case for this change?

This allows for Reconciler implementations to customize their configuration based on runtime information before being registered in situations where programmatic configuration via manually created ControllerConfigurationOverrider might not be easy or straightforward, like the Quarkus extension (and could potentially simplify the Spring Boot starter as well).

[goldmann]

I like this approach. It will definitely make my life easier where I have many label selectors that I'm adjusting based on two sources: a Map in the code and env variables set at deployment time. And this multiplied by a number of controllers.

[xstefank]

The only thing I don't understand is why it's not applied the first time getConfigurationFor is called.