Add eth2 provider

[spacesailor24]

Description

• Adds web3-eth2-core package
• Adds web3-eth2-beaconchain package

Notes

• web3-eth2-beaconchain has a file located in web3-eth2-beaconchain/src/schema.ts where all the supported API methods are defined

Why is this a draft

• Lodestar types are not properly implemented for API wrapper methods
• [ ] Some methods listed in web3-eth2-beaconchain/src/schema.ts are not implemented in Lodestar yet (need to verify with Lodestar team)
• [ ] Some implemented methods don't return expected values based off official spec

Created an issue to track the following:

• Some methods listed in web3-eth2-beaconchain/src/schema.ts are not implemented in Lodestar yet (need to verify with Lodestar team)
• Some implemented methods don't return expected values based off official spec

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run dtslint with success and extended the tests and types if necessary.
• I ran npm run test:unit with success.
• I ran npm run test:cov and my test cases cover all the lines and branches of the added code.
• I ran npm run build and tested dist/web3.min.js in a browser.
• I have tested my code on the live network.
• I have checked the Deploy Preview and it looks correct.
• I have updated the CHANGELOG.md file in the root folder.

[coveralls]

Coverage remained the same at 80.393% when pulling b61f87f on wyatt/eth2-refactor into 16320d2 on 1.x.

[frankiebee]

THANK YOU! 🥳