Expose blockchain events in the REST API

[LefterisJP]

Problem Definition

Blockchain events are not exposed in the REST API.

Solution

Add endpoints for the blockchain events in the REST API.

Tasklist

• Add functions to retrieve the blockchain events in the programmatic API.
• Create Rest API endpoints wrapping the blockchain events.

Notes

An improvement over the implementation tracked by this issue would be to use eth_getLogs to reduce the number of RPC calls. This improvement is tracked by the following issue: #452

[LefterisJP]

Pull Requests implementing the required functionality:

1. Add blockchain event getter functionality in the programmatic API

[LefterisJP]

Hmmm we forgot to label this issue with an estimate. My bad, forgot to ask you to vote right after making the issue. I will put a 3 for now for the retrospective purposes.