$feature_flag_called should be triggered again for an already trigged flag if there are new values

[marandaneto]

Version

Latest

Steps to Reproduce

Relates to PostHog/posthog-js-lite#281
Read a flag
Reload flags
Read a flag
$feature_flag_called is captured only the first time is called, but not the 2nd which is fine when the result doesn't change, but if it does, it should be triggered.
Since we don't keep track of the results, we just clear the Set that check if flags were captured or not after the flags are reloaded.

The very same issue happens on Android

• Android
• iOS

Expected Result

$feature_flag_called event is captured again with the new value

Actual Result

$feature_flag_called event isn't captured again