chore: renaming noop span to non recording span

[obecny]

Fixes #41

[codecov]

Codecov Report

Merging #43 (da4b1ae) into main (9fba460) will not change coverage.
The diff coverage is 85.71%.

@@           Coverage Diff           @@
##             main      #43   +/-   ##
=======================================
  Coverage   94.61%   94.61%           
=======================================
  Files          39       39           
  Lines         501      501           
  Branches       81       81           
=======================================
  Hits          474      474           
  Misses         27       27           

Impacted Files	Coverage Δ
src/trace/NoopTracer.ts	95.45% <75.00%> (ø)
src/context/context.ts	92.50% <100.00%> (ø)
src/trace/NonRecordingSpan.ts	100.00% <100.00%> (ø)

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[Flarna]

Should we add a Upgrade guidelines section in readme for breaking changes similar as in core repo?