Count is not incremented when manually constructing download url

Problem/Motivation

When manually constructing a download url as the Media Entity Download project description explains:

$url = Url::fromRoute(
  'media_entity_download.download',
  [
    'media' => $media_id,
  ],
  [
    'query' => [
      'delta' => $delta,
    ],
  ]
);

The counter is not incremented.

Proposed resolution

Make the module more robust by replacing media_entity_download_count_file_access() (which is more of a hack/workaround than a solid solution) with a request event subscriber that triggers every time the media_entity_download.download route is visited. This way, there aren't any accidental increments when file access is checked. Also, because we have direct access to the media entity, the logic becomes a lot simpler.

This indirectly fixes the following issues as well:

• #3518039: media_entity_download_count_file_access() doesn't account for empty response from file_get_file_references()
• #3350813: The media_entity_download_count_file_access function doesn't skip the /media/add/X path properly

User interface changes

None.

API changes

None.

Data model changes

None.