Drop internal/log package

internal/log has been introduced while developing the topology controller in order to easy our path towards structured logging.

Now that structured logging is well integrated in klog and we have clear logging guidelines I think we can drop this package (eventually we can add by simply adding a couple of utility func to the topology controller, TBD)

/area topology /kind cleanup

cc @ykakarap @sbueringer @killianmuldoon opinions?