Improve log message output of loader.
Improve log message output of loader.

- Message name (i.e. directory) is printed as well as the ID from the
  originating queue. Should help locate messages.
- General imporvements to log formatting and consistency.

tofu-rocketry/apel,stfc/apel,stfc/apel,tofu-rocketry/apel,apel/apel,apel/apel