perf(sdk-trace-base): optimize Span.{addEvent,addLink} performance#6516

dyladan merged 2 commits intoopen-telemetry:mainopen-telemetry/opentelemetry-js:mainfrom

daniellockyer:perf/span-bench-addEvent-addLinkdaniellockyer/opentelemetry-js:perf/span-bench-addEvent-addLinkCopy head branch name to clipboard