Add more ledger details to getLedger/getLatestLedger

[leighmcculloch]

The getLatestLedger endpoint should return all information about the ledger, such as the ledger header, and any other details the rpc knows about the ledger.

Currently it only reports the following:

❯ http POST :8000/soroban/rpc jsonrpc=2.0 id=0 method=getLatestLedger
HTTP/1.1 200 OK
Accept-Post: application/json
Connection: keep-alive
Content-Length: 148
Content-Type: application/json
Date: Sat, 24 Feb 2024 00:03:04 GMT
Server: nginx/1.18.0 (Ubuntu)
Vary: Origin
Vary: Origin

{
    "id": "0",
    "jsonrpc": "2.0",
    "result": {
        "id": "171f5f42a7375f17a10b9633c063ec35291a6253e9f309d13d31a55933f537ed",
        "protocolVersion": 20,
        "sequence": 283919
    }
}

Related to:

• Add a getLedger endpoint #78

[aditya1702]

getLatestLedger should include the same info that we decide for getLedgers implementation. Both tickets can be combined together. cc @Shaptic @2opremio