Support for Enriched flag analytics

[marandaneto]

Description

Description

follow up PostHog/posthog-android#191
https://posthog.com/docs/libraries/js/usage#enriched-flag-analytics

• Android
• iOS
• Flutter
• RN

[MohitMandalia]

this can probably be closed.

[marandaneto]

not all SDKs have setPersonPropertiesForFlags or similar, I think, have to double check