node-integration-tests: port trace semantics suites to span streaming #24140

Follow the porting recipe in the parent issue.

Sampling, DSC, envelope headers and span linking. These suites assert on envelope headers and trace propagation rather than on instrumentation output, so they are the ones most likely to expose a real product bug rather than a test rewrite.

Suites

• Envelope headers and DSC: tracing/envelope-header/* (7 dirs), tracing/dsc-txn-name-update, tracing/double-baggage/* (3 dirs), tracing/meta-tags, tracing/meta-tags-twp, tracing/meta-tags-twp-errors
• Sampling: tracing/sampling-static, tracing/sample-rate-propagation/* (4 dirs), tracing/sample-rand-propagation, tracing/no-parent-span-client-report
• Trace lifetime: tracing/continueTrace, tracing/startNewTrace, tracing/traceid-recycling, tracing/traceid-recycling-with-spans
• Span shaping: tracing/linking, tracing/maxSpans, tracing/tracer-start-active-span-error
• Public API span surface: public-api/startSpan/* (7 dirs), public-api/beforeSendSpan-static, public-api/bindScopeToEmitter, public-api/setMeasurement, public-api/scopes/*

Twins to fold back

tracing/sampling-streamed, tracing/ignoreSpans-streamed/*, public-api/beforeSendSpan-streamed, context-streamed/*, and the 6 public-api/startSpan/*-streamed dirs.

Keep static trace lifecycle coverage

This is the group that owns the guard. Keep tracing/sampling-static and public-api/beforeSendSpan-static on the static pin. Everything else moves.