DIGIT-2819 Add Rack Stack span and normalize Queue Time span type/subtype#4

niltonvasques merged 3 commits intooxeanbits:oxean-forkoxeanbits/apm-agent-ruby:oxean-forkfrom

gustoliveira:create-rack-stack-spangustoliveira/apm-agent-ruby:create-rack-stack-spanCopy head branch name to clipboard