Decouple RetryConfiguration from Retry

[csviri]

ATM, Retry interface extends RetryConfiguration.
However RetryConfiguration is specific to the GenericRetry impementation. So these needs to be decouple.

see: https://github.com/java-operator-sdk/java-operator-sdk/blob/af239f41f9be1eec9feaac16c6b2d9ec295fc907/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/retry/Retry.java#L5-L5