Shenandoah gc parsing, groupByFields, InputStreamFeeder

• added Shenandoah gc parsing for jmx.
• runs on java 11+ (not on java 8 anymore).
• improvements for httpStatus and httpCode via groupByFields
• use maxUniqueCounters everywhere
• improved pc error message wrong command line order
• added processing of InputStreams via InputStreamFeeder, fix for logback parsing with directives before curlies, as in: %X{name}