Add zap log bridge

[pellared]

Add zapcore.Core log bridge.

[pellared]

@khushijain21 is working on it.

[khushijain21]

Outline of the approach

• Skeleteon of zapcore and config for the bridge
• Implement Enabled, Check method
• Implement zapcore encoder
• Implement With and Write method
• Add Benchmarks

[pellared]

1. We do not need to implement zapcore.Encoder as we are providing a zapcore.Core
2. You can first implement Write and then With method as separate PRs
3. You can handle https://pkg.go.dev/go.uber.org/zap/zapcore#NamespaceType as a separate PR
4. You can handle trace correlation (handling context.Context) as a separate PR
5. After benchmarks are in place we can add performance improvements. I suggests adding usage of sync.Pool and other improvements after benchmarks are in place and we have required functionality in place.
6. Go doc comment should be updated after the implementation is done.
7. A testable example should be added demonstrating how to setup otelzap.
8. After the release the Go module should be added to https://opentelemetry.io/ecosystem/registry
9. After the release we could document the bridge also in https://opentelemetry.io/docs/languages/go/