feat: span processor onstart recieves context

[dyladan]

Fixes #1613

[codecov]

Codecov Report

Merging #1632 into master will increase coverage by 1.43%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1632      +/-   ##
==========================================
+ Coverage   90.86%   92.30%   +1.43%     
==========================================
  Files         151      147       -4     
  Lines        4358     4653     +295     
  Branches      885      956      +71     
==========================================
+ Hits         3960     4295     +335     
+ Misses        398      358      -40     

Impacted Files	Coverage Δ
packages/opentelemetry-tracing/src/Tracer.ts	98.33% <ø> (ø)
...s/opentelemetry-tracing/src/BasicTracerProvider.ts	77.77% <100.00%> (ø)
...es/opentelemetry-tracing/src/MultiSpanProcessor.ts	100.00% <100.00%> (ø)
...ges/opentelemetry-tracing/src/NoopSpanProcessor.ts	42.85% <100.00%> (ø)
packages/opentelemetry-tracing/src/Span.ts	98.09% <100.00%> (ø)
...s/opentelemetry-core/src/platform/node/sdk-info.ts	0.00% <0.00%> (-100.00%)	⬇️
.../opentelemetry-api/src/platform/node/globalThis.ts	0.00% <0.00%> (-100.00%)	⬇️
...pentelemetry-core/src/platform/node/performance.ts	0.00% <0.00%> (-100.00%)	⬇️
...ckages/opentelemetry-core/src/common/NoopLogger.ts	40.00% <0.00%> (-20.00%)	⬇️
packages/opentelemetry-propagator-b3/src/common.ts
... and 31 more