Unembed SpanContext

[IrisTuntun]

Unembed SpanContext in Link so that Link can be correctly Marshaled. Should resolve #1820 .

[codecov]

Codecov Report

Merging #1877 (449f7b7) into main (b7d02db) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #1877   +/-   ##
=====================================
  Coverage   78.7%   78.7%           
=====================================
  Files        137     137           
  Lines       7339    7339           
=====================================
+ Hits        5780    5782    +2     
+ Misses      1317    1316    -1     
+ Partials     242     241    -1     

Impacted Files	Coverage Δ
trace/trace.go	86.7% <ø> (ø)
exporters/otlp/internal/transform/span.go	98.1% <100.0%> (ø)
exporters/trace/jaeger/jaeger.go	92.8% <100.0%> (ø)
sdk/trace/batch_span_processor.go	87.1% <0.0%> (+1.5%)	⬆️