Add more transports, schema validation and refactorings

[lucifer4j]

This PR covers a lot of stuff.

• Add Websockets and HTTP transports in addition to the existing TCP transport for the JSON RPC bridge.
• The Websockets transport can be configured to send messages in text or binary.
• A basic JSON schema is included in the resources and loaded from classpath at runtime to validate the messages received on the bridge.
• Add separate tests for each transport.
• Message Type Support
  • Websockets and TCP support all message types.
  • The HTTP transport does not support publish/send from server to client and unregister method.
  • HTTP transport supports SSE.
• HTTP transport has a convenience method to access SSE because SSE doesn't allow POST or request body.
• Adds demos for all transports.
• Lots of refactorings around writing the message, see commits for more details.