remove old v0 errors from js sdk. provide error details to the user

[glitch003]

Users often get the error "There was an error getting the signing shares from the nodes". We should aim to include any details we have from the node, and not just return this opaque error. IMO the "After" message below is a lot better - it clearly indicates that there was a timeout.

We can still improve this a lot, but this is just a quick fix to ensure that the user can at least see what's coming out of the node. In reality, this timeout error should be a specific error code, etc, but that might be something we need to fix on the node side (aka, the node isn't returning a proper error code in this case, and it's returning some unknown error, but at least that error has details that help with debugging)

Before:

"error": {
      "message": "There was an error getting the signing shares from the nodes.",
      "errorKind": "UnknownError",
      "errorCode": "unknown_error"
    }

After:

"error": {
      "message": "There was an error getting the signing shares from the nodes",
      "errorCode": "unknown_error",
      "errorKind": "Timeout",
      "status": 500,
      "details": [
        "timeout limit reached timeout limit: 31000ms"
      ],
      "requestId": "a3073ee78572a"
    }

Or, in the case where we just didn't get enough shares:

"error": {
      "message": "The total number of valid signatures shares 2 does not meet the threshold of 4",
      "errorCode": "no_valid_shares",
      "errorKind": "Unexpected",
      "requestId": "d44599bd20edf"
    }

[FedericoAmura]

This is not related to this PR. Can we remove?

[glitch003]

it's the only way i can get it to build consistently :(

anson's optimise/1 branch also fixes the build for me. so my plan is to remove --parallel=false when his optimise/1 branch lands. if we merge optimise/1 first then we could remove --parallel=false now.