Remove StatusCode::as_str

[jtescher]

The spec does not define a string representation, this was a jaeger-specific conversion.

[codecov]

Codecov Report

Merging #741 (517f8bd) into main (5f1bd35) will decrease coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #741      +/-   ##
==========================================
- Coverage   70.49%   70.46%   -0.04%     
==========================================
  Files         108      108              
  Lines        8755     8752       -3     
==========================================
- Hits         6172     6167       -5     
- Misses       2583     2585       +2     

Impacted Files	Coverage Δ
opentelemetry-api/src/trace/span.rs	84.61% <ø> (+0.24%)	⬆️
opentelemetry-jaeger/src/exporter/mod.rs	59.76% <100.00%> (+0.09%)	⬆️
opentelemetry-sdk/src/metrics/controllers/push.rs	80.00% <0.00%> (-3.34%)	⬇️
...elemetry-sdk/src/metrics/aggregators/last_value.rs	42.30% <0.00%> (-0.83%)	⬇️
opentelemetry-sdk/src/metrics/aggregators/array.rs	32.09% <0.00%> (-0.41%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5f1bd35...517f8bd. Read the comment docs.