[block-producer]: redesign tracking issue

[Mirko-von-Leipzig]

The block-producer redesign feature is being developed against the next-block-producer branch until it is ready to merge into next proper.

This issue tracks the remaining work after #502, initially derived from this comment.

• input and output note state tracking
• data propagation from mempool to batch and block builders
• batch builder with configurable failure/work rate
• block builder with configurable failure/work rate
• tests
• replacing existing framework
• Support transaction expiration #508
• [block-producer]: follow-up tasks #519
• Batch building should use arcs #531

[bobbinth]

@Mirko-von-Leipzig - should we close this issue?