Need a parser for 'rabbitmqctl_report' of containers

[xiangce]

The existing rabbitmq_report spec and RabbitmqReport parser only collect and parse the file get from the host. There are rules need to analyze the same files in the guest containers.

Better add a new parser for the file of containers. And the files are in the same format, but from different paths, the existing RabbitmqReport parser can be used as the basic parser.

See: #2045

[xiangce]

Due to the container strategy does not get a conclusion yet, currently, there is not a good method to collect the files in a container. (docker exec is not suggested).
See: RedHatInsights/insights-core-assets#189

For insights-archives, We may need to wait for a while to add this parser, until container strategy get decided.

But for sos-archives, it's totally OK to add this parser

[zerodayz]

@xiangce Note that from RHEL 8 we have podman and not docker

[xiangce]

@zerodayz - May you tell me what's the name of the file in a sos-archive collected in RHEL 8?