Logs SDK design

[pellared]

Create a design for Logs SDK similarly to #4809.

Prior art: #3606

[MrAlias]

Talking with @pellared offline, we likely want to try and use the OTLP proto as our data model if we can for the SDK:

• it is the only expected output format
• it will help preserve the optimizations we how to provide by default

We will need to look into if this is feasible. Namely, if it can be done without taking a dependency on gRPC.

[pellared]

We will need to look into if this is feasible. Namely, if it can be done without taking a dependency on gRPC.

Related issues:

• Split go.opentelemetry.io/proto module to exclude grpc dependencies opentelemetry-proto-go#100
• otlp*http modules import grpc #2579

[pellared]

SIG meeting:
Depending on OTLP Go-proto as our data model may lead to issues as there are no guarantee that protoc-gen-go will always generate backwards-compatible code. It would be safer if SDK defines the data model unless the benchmarks will show significant differences to favor Go-proto code.