feat: add AdEvent enum to have an exhaustive list of all possible AdEvent values

[avencat]

To test this PR, you have to enable ads in your project, see:
https://react-native-video.github.io/react-native-video/component/props#adtagurl (it appears the link needs to be fixed too) and iOS and Android parts of https://react-native-video.github.io/react-native-video/installation

• On iOS, add this to your Podfile:

$RNVideoUseGoogleIMA = true

• On Android, add this to buildScript.ext section of your android/build.gradle file:

        RNVUseExoplayerIMA = true

Then, you should be able to do:

import { AdEvent } from 'react-native-video'

const MyComponent = () => {
  const onReceiveAdEvent = (adEvent: AdEvent) => {
    if (adEvent === AdEvent.COMPLETED) {
      console.log('Ad completed!');
    } else {
      console.log(adEvent);
    }
  };

  return (
    <Video
      adTagUrl='https://pubads.g.doubleclick.net/gampad/ads?iu=/21775744923/external/vmap_ad_samples&sz=640x480&cust_params=sample_ar%3Dpremidpostoptimizedpodbumper&ciu_szs=300x250&gdfp_req=1&ad_rule=1&output=vmap&unviewed_position_start=1&env=vp&impl=s&cmsid=496&vid=short_onecue&correlator='
      onReceiveAdEvent={onReceiveAdEvent}
    />
  );
};

[freeboub]

Thank you !
Can you just confirm I shall merge #3373 before ?

[avencat]

@freeboub yes exactly, because otherwise the types won't be accurate for iOS! 😕

[KrzysztofMoch]

Thanks @avencat 🚀