Add support for consent-aware event caching

[tustanivsky]

Currently, when user consent is required but not granted, crash events are discarded immediately. This means that if a user initially declines consent and later changes their mind, any crashes that occurred before consent was granted are permanently lost.

The desired behavior is to cache events/crashes locally on disk (if caching is enabled) when user consent is not given, and automatically send them once consent is later granted.

[linear]

NATIVE-166

[jpnurmi]

Thanks for the proposal. Makes sense, and should be doable once we have HTTP retries (#1520).