Add utility classes and tests for Timer and Attribute tracking by id …#1614

GrzegorzDrozd wants to merge 1 commit intoopen-telemetry:mainopen-telemetry/opentelemetry-php:mainfrom

GrzegorzDrozd:util-timers-and-attributes-trackersGrzegorzDrozd/opentelemetry-php:util-timers-and-attributes-trackersCopy head branch name to clipboard