Bounties: Oracle should transfer rewards to workers or slash their accounts at the judgement stage

When the oracle submits a judgement he already has to iterate the entries he is judging, when he decides an entry is a winner, the oracle must attribute a reward to that entry, if the oracle already knows the worker_member_id and the amount to reward, he can get the controller worker account id and transfer that amount right away.
If the oracle decides an entry is rejected he can slash the worker staking account immediately.

This saves the workers from having to call a new extrinsic and query the entries store.
This change makes the field EntryRecord::oracle_judgmnt_result useless

If a worker submitted some work that didn't get judged, he can unlock his stake by calling unlock_work_entrant_stake