add support for env var configuration to otlp/gRPC

[paivagustavo]

• Added env var config to the otlp/gRPC driver.
• I did a small refactor to the otlp/HTTP options to make it reusable in the otlp/gRPC driver.
• Since I needed to refactor both drivers to accept different connection and configuration when sending data to traces and metrics, I've also added some more context to some errors.

[codecov]

Codecov Report

Merging #1811 (c6501ca) into main (d616df6) will decrease coverage by 0.1%.
The diff coverage is 81.7%.

@@           Coverage Diff           @@
##            main   #1811     +/-   ##
=======================================
- Coverage   78.6%   78.4%   -0.2%     
=======================================
  Files        134     135      +1     
  Lines       7158    7236     +78     
=======================================
+ Hits        5630    5679     +49     
- Misses      1278    1307     +29     
  Partials     250     250             

Impacted Files	Coverage Δ
exporters/otlp/otlpgrpc/options.go	44.4% <44.4%> (-43.1%)	⬇️
exporters/otlp/otlphttp/options.go	56.0% <54.1%> (-36.5%)	⬇️
exporters/otlp/otlpgrpc/connection.go	92.5% <78.5%> (+3.7%)	⬆️
exporters/otlp/otlpgrpc/driver.go	88.7% <88.0%> (-1.5%)	⬇️
exporters/otlp/internal/otlpconfig/options.go	90.8% <90.8%> (ø)
exporters/otlp/internal/otlpconfig/envconfig.go	92.5% <94.4%> (ø)
exporters/otlp/otlphttp/driver.go	94.6% <100.0%> (+<0.1%)	⬆️

[paivagustavo]

I've just noticed that this does implement the timeout option that should exist in the gRPC exporter as well. I'll tackle down this in another PR.

[MrAlias]

I've just noticed that this does implement the timeout option that should exist in the gRPC exporter as well. I'll tackle down this in another PR.

Does this mean that #1085 should not be closed by this PR @paivagustavo?

[paivagustavo]

I've just noticed that this does implement the timeout option that should exist in the gRPC exporter as well. I'll tackle down this in another PR.

Does this mean that #1085 should not be closed by this PR @paivagustavo?

Yes, I'll update this PR description to not close the issue.