Span Streaming Implementation

[Lms24]

Problem Statement

This issue collects steps we need to take to implement span streaming

some deeper thoughts on various related topics: #17798

Solution Brainstorm

In a rough order and once we are ready to bring this into our develop branch:

• [core] Define envelope and serialized span types
• [core] Implement span JSON serialization
• [core] Implement client hooks required for sending, buffering and span processing
• [core] Add new traceLifecycle SDK option
• [core] Adjust beforeSendSpan type and export makeV2Callback helper function
• [everywhere] migrate SDK-internal event processor usage for transaction events to client hook (see Implications of Span Streaming #17798)
• [browser] implement buffering and sending logic in integration
• [node] implement buffering and sending logic in new OTel Span Processor/Exporter
• [everywhere] apply context data to segment span as attributes
• [meta] define any missing attributes in sentry conventions
  • e.g. Web Vital Conventions sentry-conventions#37
• ~~[core] set SpanKind and ~~isRemote~~ on ~~~~SentrySpan~~
• ~~[core] extract span ~~kind~~ and ~~is_remote~~ form ~~SentrySpan~~ and OTel ~~~~Span~~
• [core, meta] define and add a client report reason for ignoreSpans

[linear]

JS-1010