Introduce deregistration period for provider/bidder registries

[shaspitz]

The validator registry contracts all have behavior where an actor needs to take an intermediate step for de-registration. They request dereg, wait a period of blocks (or time), then fully deregister with a second tx. See this example https://github.com/primev/mev-commit/blob/514339d71ac842718491a6a0e39252b422abdab3/contracts/contracts/validator-registry/VanillaRegistry.sol#L306.

This functionality needs to be added to the provider and bidder registries using already created libs

[ckartik]

This already exists, but we need to make sure the mev-commit node actually de-registers them when the stake is withdrawn.