Create a port of media_entity_instagram compatible with media in core API

This should be added in a new branch.
The old branch can be deprecated when 8.5/8.6 gets in.

Nice work Marcos,

It works pretty good. Just one thing i discovered is that the thumbnail is not generated.

And maybe we should ship some default configuration, like we do in core now.

1. +++ b/media_entity_instagram.info.yml
   @@ -4,4 +4,5 @@ type: module
   +  - drupal:media
   +  - drupal:system (>= 8.4.0)
   

   Why not just drupal:media (>= 8.4.0)

2. +++ b/media_entity_instagram.install
   @@ -9,7 +9,13 @@
   +  foreach ($files as $file) {
   +    file_unmanaged_copy($file->uri, $destination, FILE_EXISTS_ERROR);
   +  }
   

   See media.install for their example. There is another if statement in there that ensures we don't overwrite an icon that may already exist.

3. +++ b/src/Plugin/media/Source/Instagram.php
   @@ -15,20 +16,15 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
   + * @MediaSource(
     *   id = "instagram",
     *   label = @Translation("Instagram"),
   - *   description = @Translation("Provides business logic and metadata for Instagram.")
   + *   description = @Translation("Provides business logic and metadata for Instagram."),
   + *   allowed_field_types = {"string", "string_long", "link"},
   + *   default_thumbnail_filename = "instagram.png"
     * )
   

   does link make sense here?

Thank you everyone