Better Support for "NO_DATA_FOUND"

[poxman]

openVulnQuery --asa 9.18.4.29

There are no advisories that affect 9.18.4.29, so the API returns a 404 with an error message:
{
"errorCode": "NO_DATA_FOUND",
"errorMessage": "No advisories found"
}

The client isn’t handling that.

Similarly for:
openVulnQuery --bugid CSCwe61917

That Bug ID is not in any of our external vulnerability databases. It is in BST but since we never published an advisory on this; it isn’t recorded in the OpenVuln API.

{
"errorCode": "NO_DATA_FOUND",
"errorMessage": "No data found"
}