Improve the way that JS is attached

2 things need to be checked:

1. In media_entity_facebook_library_info_build():
+ $language_id = \Drupal::languageManager()->getCurrentLanguage()->getId() ?? 'en_US';

We cannot really use this as FB SDK's langcodes differ from Drupal's. The proper langcode-map is already there in FacebookFetcher $langcodes array. That array needs to be refactored to a service that contains one public method getFacebookSdkLangcodeByDrupalLangcode($drupalLangcode) and that should be called in this hook.

2. Also, in the patch does this library load for every single page? It should load only if a Facebook media is rendered.

Also, note for myself: if we change the way how we attach libraries, then the Facebook cookie consent module we made → also needs a new way of blocking the FB SDK script.

@kaszarobert Thanks for looking at the patch.

In regards to point 2. It only loads when the template media-entity-facebook is rendered and is_frame is FALSE.

I'll take a look at the language mapping and make the necessary changes.

@kaszarobert Sorry for the delay in getting this done.