searchattribute: quote name in error messages

[ikonst]

What changed?

Quote the name to clarify it's not part of the prose.

Why?

I've got this response from the service, and it took me a while to grok that 'method' was in fact the name of my search attribute:

{
  "code": 3,
  "details": "search attribute method is not defined",
  "metadata": {
    "content-type": [
      "application/grpc"
    ]
  }
}

How did you test it?

I'm terrible.

Potential risks

Someone parsing those error messages?