Span Streaming Implementation

[Lms24]

This issue tracks steps for getting #17852 step by step into a reviewed and cleaned up state.

• Span and envelope type definitions (feat(core/spans): Add span v2 and envelope type definitions #19100)
• Public API to opt into span streaming (feat(core): Add traceLifecycle option and beforeSendSpan compatibility utilities #19120)
• Span Serialization Utilities (feat(core): Add span serialization utilities #19140)
• Span envelope creation (feat(core): Add StreamedSpanEnvelope creation function #19153)
• captureSpan pipeline (feat(core): Add captureSpan pipeline and helpers #19197)

To do:

• PR 9: SpanBuffer Class - New class for buffering spans before sending
• PR 13: shouldIgnoreSpan and reparentChildSpans Updates - Update to support both SpanJSON and SpanV2JSON
• PR 14: Core spanStreamingIntegration (Server) - New server-side span streaming integration
• PR 15: requestDataIntegration Span Streaming Support - Add processSegmentSpan hook handler
• PR 16: nodeContextIntegration Updates - Set contexts on global scope, update span scope on spanEnd
• PR 17: OpenTelemetry StreamingSpanExporter - New streaming exporter for OpenTelemetry integration
• PR 18: Browser spanStreamingIntegration - Browser-specific span streaming integration
• PR 19: Browser httpContextIntegration Updates - Add processSegmentSpan hook for span streaming
• PR 20: Browser Web Vitals as Attributes (CLS, LCP) - Use startInactiveSpan with attributes for CLS/LCP
• PR 21: Browser Web Vitals INP and TTFB Updates - Send INP as V2 span when streaming, set web vitals as attributes
• PR 22: browserTracingIntegration Updates - Deprecate standalone span options, use hasSpanStreamingEnabled
• PR 23: SDK Re-exports (withStreamSpan) - Export withStreamSpan from browser, node, and node-core packages
• PR 24: Test Utilities for Span V2 - Add waitForSpanV2Envelope, waitForSpanV2, waitForSpansV2 utilities
• PR 25: Browser Integration Test Utilities - New utilities for browser integration tests
• PR 26: Node Integration Tests for Span Streaming - Integration tests for default span streaming and ignoreSpans
• PR 27: Browser Integration Tests for Span Streaming - Tests for pageload, error, linked-traces, measurements, web-vitals, backgroundtab-pageload
• PR 28: Size Limit and Cleanup - Update size limits and add changelog entries

[linear]

JS-1010