fix #379, add significantly more error logging

[northdpole]

closes #379
adds logs such as:

csearch: ","scanID":"","error":"could not contact Elasticsearch, attempted to retrieve cluster 
info and got status code: 401 as a result, body: [401 Unauthorized] {\"error\":{\"root_cause\":
[{\"type\":\"security_exception\",\"reason\":\"unable to authenticate with provided credentials
 and anonymous access is not allowed for this request\",\"additional_unsuccessful_credentials\"
:\"API key: unable to find apikey with id kkttHpIBE8LvqBqM9yuN\",\"header\":{\"WWW-Authenticate
\":[\"Basic realm=\\\"security\\\", charset=\\\"UTF-8\\\"\",\"Bearer realm=\\\"security\\\"\",\
"ApiKey\"]}}],\"type\":\"security_exception\",\"reason\":\"unable to authenticate with provided
 credentials and anonymous access is not allowed for this request\",\"additional_unsuccessful_c
redentials\":\"API key: unable to find apikey with id kkttHpIBE8LvqBqM9yuN\",\"header\":{\"WWW-
Authenticate\":[\"Basic realm=\\\"security\\\", charset=\\\"UTF-8\\\"\",\"Bearer realm=\\\"secu
rity\\\"\",\"ApiKey\"]}},\"status\":401}"}```

when the api key cannot contact elasticsearch at all

and similar for when the index does not exist