Consensus improvements

[n-hutton]

There are some items that are known to be incorrect in consensus, but are non-blocking:

• The finalized block algoritm could be more lenient. A block can be finalized if it's child is view + 1 and that child has a child (regardless of whether view is contigous). Currently both child and grandchild have to be contiguous in view (N+1, N+2).
• When there are not enough validators online to produce the next block it cycles, creating forks at the HEAD, where each proposed block in the fork is the step change to the insufficient committee. By making aggQC require all of the validators to sign newView, this cycling will not happen (but it will still create a fork when enough validators come online).
• adding a configurable delay to block generation for testing purposes
• consider using an iterator for key compression in BLS function