update sampler to take a context and update some names to match spec

[tsloughter]

No description provided.

[codecov]

Codecov Report

Merging #134 into master will increase coverage by 0.17%.
The diff coverage is 90.24%.

@@            Coverage Diff             @@
##           master     #134      +/-   ##
==========================================
+ Coverage   32.13%   32.30%   +0.17%     
==========================================
  Files          63       63              
  Lines        2981     2990       +9     
==========================================
+ Hits          958      966       +8     
- Misses       2023     2024       +1     

Flag	Coverage Δ
api	46.44% <100.00%> (ø)
elixir	16.24% <0.00%> (ø)
erlang	32.15% <90.24%> (+0.17%)	⬆️
exporter	17.05% <ø> (ø)
sdk	65.11% <89.74%> (+0.30%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ntelemetry_exporter/src/opentelemetry_exporter.erl	61.11% <ø> (ø)
apps/opentelemetry/src/otel_sampler.erl	88.37% <80.00%> (-1.38%)	⬇️
apps/opentelemetry/src/otel_span_ets.erl	59.45% <87.50%> (+0.63%)	⬆️
apps/opentelemetry/src/otel_span_utils.erl	96.55% <93.33%> (+4.88%)	⬆️
apps/opentelemetry/src/otel_batch_processor.erl	72.72% <100.00%> (-0.84%)	⬇️
apps/opentelemetry/src/otel_propagator_http_b3.erl	64.51% <100.00%> (ø)
...pps/opentelemetry/src/otel_propagator_http_w3c.erl	45.45% <100.00%> (ø)
apps/opentelemetry/src/otel_tracer_default.erl	100.00% <100.00%> (+4.54%)	⬆️
apps/opentelemetry_api/src/otel_tracer.erl	58.33% <100.00%> (ø)

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[ferd]

Is this a spec thing or just wondering?

[tsloughter]

Yea. It is something we need to figure out next and I gave up on completely solving in this PR.

I'm unsure if we need an actual #span{} in the ets table for a recorded but not sampled span.