[FEATURE] Implement Logging Hook

[toddbaert]

Requirements

• Implement a logging hook as described in appendix A of the OpenFeaure spec: https://github.com/open-feature/spec/blob/main/specification/appendix-a-included-utilities.md#logging-hook
• Remove all logging from evaluation lifecycle (hot path)

Java implementation: open-feature/java-sdk#1084

[liran2000]

hi @toddbaert @Kavindu-Dodan,
I am looking at this issue,
I think it can be implemented via slog from standard GO library, but as it started since GO 1.21 and go-sdk is still at GO 1.20, PR can be prepared, and can be merged later when go-sdk move to GO 1.21.
what do you think ? and when go-sdk planned to move to GO 1.21 ?

[Kavindu-Dodan]

@liran2000 the SDK should already be on Go 1.22 as latest supported versions are 1.22 & 1.23. So I don't think this is a blocker.