Automate veFeeDistributor checkpoints

[alexcos20]

Due to veFeeDistributor design, we need to call checkpoint_token and checkpoint_total_supply every Thu, after 00:00.

We can do it with Gelato, but there is a caveat: Only owner is guaranteed to have success on those calls, for other addresses it may fail and rewards can fail.

Status quo: there is a multisig that owns veFeeDistributor, we generate tx from df-py and somebody signs them and executes them.

Proposal:

• write a contract that owns veFeeDistributor and it's owned by multisig (veFeeOwner.sol)
• write a gelato cron to automate checkpoint_token and checkpoint_total_supply
• remove code from df-py

[mihaisc]

@alexcos20 is this still relevant?