Provide simple way of capturing repository invocation and its executing target.

Currently there is no simple way for users to figure out which method is actually called via the RepositoryMethodInvoker since the class does not offer any kind of logging.

We should consider either adding straight forward logging statements (trace maybe) or enhancing RepositoryMethodInvocationListener.RepositoryMethodInvocation to include information, like the fragment type, about the target method.

The logger might be easier to understand as it does not require additional setup. RepositoryMethodInvocationListener is not well documented nor trivial to configure requiring a BeanPostProcessor.

Knowing the configuration we could also consider logging a report containing the method mappings once at startup.