Custom Cache Tags

The purpose of this module is to extend the Drupal 8 core list of provided cache_tags to include provisions for automated cache tagging by entity bundle (aka content types, media entities, etc) and other needed changes. This will aid in reducing the overhead required to allow users to instigate cache clearing for a narrower data set instead of, say, clearing the entire node cache just to get a new Article node to appear in a custom block.