Adds config support for GRPC and improves test assertions

[jcchavezs]

This PR adds support for config in GRPC and also improve test assertions to cover all attributes being added.

[codecov]

Codecov Report

Merging #53 (4681be1) into main (85288e6) will decrease coverage by 11.03%.
The diff coverage is 93.02%.

@@             Coverage Diff             @@
##             main      #53       +/-   ##
===========================================
- Coverage   60.67%   49.64%   -11.04%     
===========================================
  Files          24       28        +4     
  Lines         679      991      +312     
===========================================
+ Hits          412      492       +80     
- Misses        224      451      +227     
- Partials       43       48        +5     

Impacted Files	Coverage Δ
sdk/google.golang.org/grpc/server.go	83.00% <87.50%> (+1.27%)	⬆️
...rumentation/opentelemetry/database/hypersql/sql.go	66.29% <100.00%> (+0.38%)	⬆️
sdk/google.golang.org/grpc/client.go	87.87% <100.00%> (+1.21%)	⬆️
sdk/internal/config/config.go	33.33% <100.00%> (ø)
sdk/net/http/handler.go	11.71% <100.00%> (ø)
sdk/net/http/transport.go	81.25% <100.00%> (ø)
sdk/net/http/attributes.go	100.00% <0.00%> (ø)
sdk/net/http/contenttype.go	100.00% <0.00%> (ø)

---

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 85288e6...4681be1. Read the comment docs.