Memoize tap GH state for sending proper value after releasing finger

[osdnk]

Motivation

Issue happens on iOS. #476.

After releasing finger in tap GH which is waiting for second GH and failure of second GH, values are being set zero and then zeros are send to JS instead on corrects values.

Changes

After reseting values are memoized and placed in nativeEvent. If this kind of situation is detected (no finger on screen) we fallback to memoized valued values instead of evaluating them.

[kmagiera]

I'd prefer if we always use memoized value for the event and memoize it in a place where we are certain the values are right. I'm not certain that the conditions you added in eventExtraData are going to work at all times (e.g. could there be a case that numberOfTouches is zero but the code where we memoize hasn't been triggered?)

[farfromrefug]

@kmagiera i think i fixed this the way you wanted.
I actually use your Native code for a Nativescript module.
Here is the commit if that is of any interest to you
nativescript-community/gesturehandler@6c3ed76

[kmagiera]

This looks more like how I'd imagine. Thanks for sending @farfromrefug. Willing to send a PR with this change maybe?

[farfromrefug]

@kmagiera sorry i dont use your code nor react-native

[jkadamczyk]

@kmagiera @jakub-gonet I can apply changes that @farfromrefug proposed.
Is it still relevant?