Ensure Parent ConfigurationClass loaded on overrides

Previously ConfigurationClassParser could override a nested
@Configuration without consideration of @Bean's defined in parent
classes.

This commit ensures that if the original ConfigurationClass contains
additional bean definitions it is processed again.

Issue: SPR-10546
(cherry picked from commit 940011e)
Properly handle knownSuperclasses in case of an overridden ConfigurationClass

Issue: SPR-10546
(cherry picked from commit 6e4317e)