Add WithEndpointURL option to OTLP over HTTP exporters

[dmathieu]

Closes #3730.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8778c38) 82.3% compared to head (50da281) 82.3%.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #4808   +/-   ##
=====================================
  Coverage   82.3%   82.3%           
=====================================
  Files        226     226           
  Lines      18421   18481   +60     
=====================================
+ Hits       15164   15224   +60     
  Misses      2971    2971           
  Partials     286     286           

Files	Coverage Δ
exporters/otlp/otlpmetric/otlpmetricgrpc/config.go	43.8% <100.0%> (+2.0%)	⬆️
...tlpmetric/otlpmetricgrpc/internal/oconf/options.go	88.4% <100.0%> (+0.9%)	⬆️
exporters/otlp/otlpmetric/otlpmetrichttp/config.go	86.6% <100.0%> (+0.9%)	⬆️
...tlpmetric/otlpmetrichttp/internal/oconf/options.go	91.4% <100.0%> (+0.7%)	⬆️
...trace/otlptracegrpc/internal/otlpconfig/options.go	94.0% <100.0%> (+0.5%)	⬆️
exporters/otlp/otlptrace/otlptracegrpc/options.go	77.3% <100.0%> (+0.8%)	⬆️
...trace/otlptracehttp/internal/otlpconfig/options.go	90.6% <100.0%> (+0.8%)	⬆️
exporters/otlp/otlptrace/otlptracehttp/options.go	100.0% <100.0%> (ø)

Non-blocking comments