[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

[kylejuliandev]

Hey @toddbaert,

I have an initial draft PR with some changes which I think address this issue. I think semantics on event numbers, log messages, and/or message formatting would need to be agreed.

I hope this is on the right track and would greatly appreciate any feedback!