Minimum daily rewards for active nodes

[Neeharika-Sompalli]

We propose a reward mechanism that will incentivize nodes to remain active on the network. The minimum reward per day for nodes will be a configurable property decided by the council. This minimum reward may be adjusted based on fees already paid throughout the day.

A node is active if it creates a judge in a significant fraction of rounds during a staking period, for example 80%.