Stake table catchup

[sveitser]

Edit: design still being finalized: https://www.notion.so/espressosys/Proof-of-Stake-Catchup-Design-17e2431b68e980cc83a0c3b5c26a094a

1. When a node comes online hotshot will ask the confirmation layer to provide the latest epoch for which the node knows the stake table.
2. It will then perform epoch wise catchup until it has the stake table for the current epoch.

The stake table is fetched from the confirmation layer but hotshot needs to verify some QCs at the end of each epoch to obtain a the header containing the finalized L1 height that determines the stake table for the following epoch. This header is passed to the confirmation layer to fetch the stake table for the following epoch.

• Add interface for confirmation layer to provide latest finalized stake table
• Perform catchup until stake table for current epoch is known