Staking implementation improvements

[gabririgo]

Summary

Implement some improvements on the staking system.

Motivation

The moveStake method does not allow moving from one pool to another in 1 single transaction, which it should. Requires staking implementation upgrade in the staking proxy. In the current staking system, a pool gets initialized in a specific epoch to participate to incentives, then is finalized at the end of the epoch. This requires two calls and all participating pools must be finalized before the 2nd next epoch. In order to save some gas, the logic could be amended.

Specification

• query pool data from pool, do not initialize staking pool
• claim reward during the epoch, without credit reward and later finalize
• directly move stake from one pool to another (currently requires deactivating and reactivating in 1 batch transaction, will save some gas)

Rationale

Notes

There is reason why the staking system is designed as such, running every 2 weeks makes it manageable from a cost perspective, but worth investigating more.