Lisk-sdk: Create forger plugin

[shuse2]

Description

Create a forging helper plugin that provides and notifies forgers with more detailed information.

Motivation

The HTTP API currently have private endpoints to enable/disable delegates, but those should be separated from the HTTP API and expanded to be more useful.

Tasks

Sprint 23

• Create package for the forging helper plugin and setup default configs #5284
• Add event listers to keep track of registered forger information #5285
• Add synchronization mechanism with framework #5286
• Create GET /api/forging/info endpoint #5287
• Create PATCH /api/forging endpoint #5288
• Create GET /api/voters #5289
• Send notification on missedBlock, createdBlock and node start and node stop #5290
• Expose decodeBlock from base plugin #5541
• Save forgers missed block information #5552
• Cleanup round calculation in forger plugin #5559
• Move /api/forgers to HTTP API plugin #5576
• Add an action to calculate next forging time for delegates #5570

Sprint 24

• Wrong calculation for votesReceived forging info #5574

Additional Information

• It should sync with the running framework blockchain information
• The config should allow one webhook URL, and event to fire. If empty, emit all
• The port should be configurable
• It should allow whitelisting IPs, by default, localhost only
• Add flag to core and register this plugin

--plugin-forger-port (LISK_PLUGIN_FORGER_PORT)
  plugin must be enabled
  Specify open port for the forger plugin

[JesusTheHun]

It would be nice to add a heartbeat endpoint, that can be called to ensure the node is healthy. Criteria are TBD but here are some ideas :

• contact with at least X node outside of the cluster recently
• database is reachable (even with embedded db, in the cloud the disk can be disconnected upon network error)
• TTFB < 200ms (the node is surviving a DDoS attack)