Improving Identity staking rewards distribution

[silva-fj]

This is the identity staking rewards distribution follow up. The main logic is as follows:

• An event is emitted to trigger the rewards distribution on each round
• The TEE Worker gets the staking amount for each account stored in Scores and calls the distribute_rewards for each account
• Then TEE Worker calls complete_rewards_distribution to indicate that the distribution for the round to all users is completed

[BillyWooo]

Please, hold on until new release goes out.

Release went out. Please proceed.