perf: ensure we do not provide callback to native if no callback provided from app

[freeboub]

Summary

As discussed with @KrzysztofMoch a possible optimization is to avoid giving callback functions (starting with 'on*') to native if application didn't provide it

Motivation

performances improvements.
Additionnally, we must keep the useCallback as paramters of the function are differents between native & applicative, for exemple:

    const _onTimedMetadata = useCallback(
      (e: NativeSyntheticEvent<OnTimedMetadataData>) => {
        onTimedMetadata?.(e.nativeEvent);
      },
      [onTimedMetadata],
    );

send e.nativeEvent to application

Changes

Just add ternary to check to avoid giving the callback to native

Test plan

Basic tests done on android/ios with the sample

[KrzysztofMoch]

I also think we should do "early returns" - because we don't need to load tracks data if user don't revive it

I will send you patch for iOS later
I will make separate PR for this

[KrzysztofMoch]

We need to add "or" condition to places that "poster" logic depends on

like

onVideoLoad={
  onLoad || hasPoster
    ? (onVideoLoad as (e: NativeSyntheticEvent<object>) => void)
    : undefined
}

[freeboub]

Good catch agin, thank you !
I integrate some of the swift fix you proposed to me also ! (but not all)

[KrzysztofMoch]

Nice let's merge this - I will make PR for "early returns" tomorrow