AnalyticsValue
A parameter or property value, carrying its type so adapters can hand vendors a real number rather than a number spelled as text.
The type decides what a dashboard can do with it: Firebase and Mixpanel can sum or average a numeric value and can only group a textual one. Vendors that accept strings only flatten it with asString.
This types the value, not its meaning — an Int called amount is still just a number to an adapter.
The variants are named for the Kotlin types they hold, so inside this declaration the wrapped types are spelled kotlin.String and so on.