Multiple issues with the Posthog Provider

[Strernd]

Hi!

I documented some issues I had and still have with setting up the posthog provider for flags-sdk and the toolbar here and here.

To summarize the issues:

• Some docs could be updated to make the integration smoother
• You are only loading activated feature flags in the adapter. Either I am using Posthog or the flags-sdk wrong, or if I'm not mistaken you should be loading all feature flags and use the returned active parameter to determine the status. You probably want to filter out deleted flags. This means I can't test flags locally now, because I always have to release them in order to view them in the explorer and being able to overwrite them.
• Hints, which seem to be a concept for your flags explorer or the Vercel toolbar in general are never forwarded to the UI.
• An empty list of flags (none setup yet) should be handled by a hint or be considered valid, otherwise the Setup process will appear stuck.

Happy to support or submit a PR if needed.

[dferber90]

Thank you for the awesome writeup, I've added this so the team will take a look!

If you feel comfortable making changes you could also open a pull request for the parts that are fixable within the @flags-sdk/posthog provider.

[Strernd]

@dferber90 I added a PR with a small change, removing the active filter from the GET call. From my understanding that should do the trick, however I might be lacking further context of the codebase to verify.

Obtaining the current value should be unaffected.

Docs improvements and showing hints in the UI are still open.