[JMX module] inconsistent use of chart properties 'family' and 'context'

[illes]

The usage of family and context in the charts generated by the java.d JMX module does not follow recommendations that may lead to inconsistent UI appearance and inconvenience when integrating with 3rd party tools.

The code at MBeanServerCollector.java#L198 does not seem to follow guidelines set forth in the wiki: https://github.com/firehol/netdata/wiki/External-Plugins#chart

The property family could rather be the identifier of the monitored JVM (serverConfiguration.getName(), the PID by default), and the context some constant across the same charts for different JVMs.

[ilyam8]

This issue was migrated from netdata-plugin-java-daemon

Closing it because netdata-plugin-java-daemon is not part of the Netdata project.