Convert block handlers and periodic operations to event listening

[RiccardoM]

Currently, we're using block handlers and periodic operations to listen to things that are updated on a periodic base, and not with messages. These include:

• delegators commissions amounts
• validator rewards amounts
• community pool updates
• inflation
• ... and many more

I think we should convert this to use an event-based listening, where we use the Tendermint websocket to listen to those events and deal them properly where possible.