add more edge cases to Query Error parser

[analogrelay]

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The backend has shifted how errors are reported a bit. Now, when we get detailed query errors from newer backends, we get a payload that looks like this:

{
    "code": "BadRequest",
    "message": "{\"code\":\"BadRequest\",\"message\":\"{\\\"errors\\\":[{\\\"severity\\\":\\\"Error\\\",\\\"location\\\":{\\\"start\\\":7,\\\"end\\\":18},\\\"code\\\":\\\"SC2005\\\",\\\"message\\\":\\\"'nonexistent' is not a recognized built-in function name.\\\"}]}\\r\\nActivityId: f9ef6130-d878-4eb9-89c9-1f525782b6c4, Windows/10.0.20348 cosmos-netstandard-sdk/3.18.0\"}"
}

Our current parsing doesn't support this (it's basically added another layer of JSON wrapping the error), so I've added support for it.

NOTE: I'm still working with the query team to get this into a format that doesn't require quite so many hacks to parse, but until then, we kinda have to just chase the weird formatting a bit. I was expecting a change like this to come, and am not expecting another change in format (until, hopefully, we can get errors reported as a top-level JSON property).