Remove bundle storage, custody manager, and router optimizer
- We do not have persistent storage.
- Thus, we cannot support custody at the moment. We also only supported it for BPv6.
- The optimizer only worked with BPv6 priorities that can be easily manipulated.
This removes the unnecessary components and fixes the deadlock #3 (closed) by dropping the back-channel from the router task to the BP, which was only necessary for invoking the custody manager.