openonu-adapter-go: trace overload in debug level usage from libraries

In situations where the adapter has to make extensive usage of OMCI message transfer and for debug reasons wants to use debeug level 'debug' the amount of log data gets critical.

In my local Vbox testing this results into abortion of the logfile at some undefined time point so that the ongoing execution of code can't be verified anymore (adpater still seems to run and behaves correctly).

Log file is retrieved in local test using 'kubectl logs ... ', as indicated by Andrea using 'kail' may behave different - not yet checked.

Critical situations for the ONU adapter are MIB upload and ONU SW download.

There is a new discussion/idea in slack fom Chip to relinquish the Kafka transport check for the OMCI transfer, which would probably also widely diminish the amount of the debug logs of the connected libraries.

On the other hand it should be considered to use some different debug level for the basic library logs: But there is already some slack comment form Andrea that such would not be easily possible:

'unfortunately ZAP does not support trace (and will not for now according to https://github.com/uber-go/zap/pull/749#issuecomment-729346609 ). So really here we are in a tight spot.'