fix: return an error on invalid voter address

[wa0x6e]

Fail early and return meaningful when voter address is invalid on vp query

Before, when passing 0x0000000000000000000000000000000000000000 or `` as voter, it calls score-api then returns:

{
  "errors": [
    {
      "message": "Unexpected error value: { code: 400, message: \"unauthorized\", data: \"invalid address\" }",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "vp"
      ]
    }
  ],
  "data": {
    "vp": null
  }
}

Now, it should return the error without calling score-api

{
  "errors": [
    {
      "message": "invalid address",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "vp"
      ]
    }
  ],
  "data": {
    "vp": null
  }
}

Test with following query

query Vp{
		vp(
			space: "rocketpool-dao.eth",
			voter: "0x0000000000000000000000000000000000000000",
		) {
			vp
		}
	}
	

[ChaituVR]

Maybe also better to check getAddress to check checksum

[wa0x6e]

We could, but this will require adding a address dependency

[ChaituVR]

utAck

[sentry-io]

Sentry issue: SNAPSHOT-HUB-1K