rpcdaemon: Set miner on eth_getBlockByNumber on Polygon

[shohamc1]

Fixes #12690

➜  ~ curl --request POST \
  -s --url http://127.0.0.1:8545/ \
  --header 'Content-Type: application/json' \
  --data '{
        "method": "eth_getBlockByNumber",
        "params": [
                "0x3F515FC",
                false
        ],
        "id": 1,
        "jsonrpc": "2.0"
}' | jq '.result.miner'
"0x83d69448f88bf9c701c1b93f43e1f753d39b2632"
➜  ~ curl --request POST \
  -s --url http://127.0.0.1:8545/ \
  --header 'Content-Type: application/json' \
  --data '{
        "method": "eth_getBlockByHash",
        "params": [
                "0xd925f567ee22d63a003f890af94c1e77e6d4d55a3bcef2b35b7b2317948d7f28",
                false
        ],
        "id": 1,
        "jsonrpc": "2.0"
}' | jq '.result.miner'
"0x83d69448f88bf9c701c1b93f43e1f753d39b2632"