Add openfeature integration

[aygalinc]

Hello !

I see you are providing a compatibility layer with IfeatureManagent but is there any plan to provide an abstraction that match openfeature spec ? https://openfeature.dev/

I can do it if you think it's the right place for this.

[aygalinc]

@haacked do you think it's the right place to do it ?
My company will bench posthog but we prefer openFeature implementation of feature management.
I can also propose some PR in OpenFeature Contrib Provider repo, it's up to you :)

[haacked]

I'm fine either way. Probably easier to maintain if it's here.