With the introduction of a Worker role in our smart contracts as part of the Alhambra Verde EPIC, we need to separate our Staker actor class in two parts: The real Staker, and the Worker.

For starters, most (all?) methods in Staker marked with the @only_me decorator seems like suitable candidates to remain in Staker. However, it seems reasonable to keep some of the "read-only" methods in Staker for Worker (i.e., get_locked_tokens).

Perhaps a "stranger" Staker (i.e., is_me=False) can be part of a Worker?