Processing of query failed errors from STDERR retrieved by ibqueryerrors

[gabrieleiannetti]

We also see errors on STDERR from ibqueryerrors that indicate collecting metrics for specific CA are failing.

In the end the errors could be collected as we did with the bad status errors.
Probably something like a query failed error metric...

The exporter prints the following right now:

2021-06-23 14:49:39,353 - ERROR - Could not process line from STDERR: ibwarn: [1203] query_and_dump: PortXmitDiscardDetails query failed on HOSTXXX, Lid 1051 port 1   
...