Fix fee catchup after restart

[jbearer]

This PR reproduces and will fix an issue discovered in staging, in which, after a staggered restart of all nodes, the network has forgotten the fee state for all accounts except those which actively produced blocks during the restart. Since the state is needed for undecided blocks, it cannot directly be obtained from persisted merklized state, which is only available for decided blocks.

This PR:

• Adds a restart-style test reproducing the issue
• TODO adds a new catchup endpoint to fetch multiple accounts at once, for performance
• TODO adds a new catchup endpoint to fetch an undecided leaf/proposal
• TODO modifies fee account catchup to recursively reconstruct fee state by searching as far back as the last decided state and replaying headers

This PR does not:

• Cache results of the recursive catchup in HotShot's state and leaf maps, to improve performance