Add governance adapter

[gabririgo]

Summary

Develop a protocol extension to allow Rigoblock smart pools to interact with the governance.

Motivation

Rigoblock pools own a substantial stake in the staking system, hence votes in the governance. In order for them to be able to participate in governance, a new adapter should be developed, deployed, and added to the protocol.

Specification

Develop a new smart contract AGovernance which allows a smart pool to make a proposal, vote on an existing proposal and execute a successful proposal. The adapter needs to be added to the protocol Authority smart contract. Its methods must be mapped in the same smart contract.

Notes

It has been deployed and added to the protocol.