Update JSON-RPC API to Condor rc2

[ipopescu]

What does this PR fix/introduce?

This PR verifies all existing methods and components in the JSON-RPCI API and updates our docs.

I've tested some methods and fields with the casper client and nctl for Condor, but not most. I relied on these files to make the updates:

• https://github.com/casper-network/casper-sidecar/blob/feat-2.0/resources/test/rpc_schema.json
• https://github.com/casper-network/casper-sidecar/blob/feat-2.0/resources/test/speculative_rpc_schema.json
  These files are kept up to date using tests.

I removed the hyperlinks next to the headings of type {#addressableentity} to make the linking work locally for me. I will add them back if needed once I test them in the staging environment. Docusaurus seems to work without them.

I updated the example request/responses to follow the following format:

Request:

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": “…”,
  "params": [
	...
  ],
}

Response:

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": {
    "name": “…”,
    "value": {
		...
	}
  }  
}

Closes #1455

Checklist

• Docs are successfully building - yarn install && yarn run build.
• My changes follow the Casper docs style guidelines.

Reviewers

@ACStoneCL

[ACStone-MTS]

Looks good to me!

[ipopescu]

Thanks @ACStoneCL!