bug: fee estimation don't have foresight

[LHerskind]

The fee estimation used for building the block is not looking into the future (the classic), so it would have issues around boundaries leading to skipped slots, but for a prune, it could cause a case where the "next" block keep being estimated using the non-pruned chain meaning that it would keep being rejected.

We can update this like we have done other times, by passing along a timestamp for the estimation function such that we can estimate for the future, and then taking into account the prune.