Issue#958/ unable to change avatar images sizes

[douglas-johnson]

Description

Resolves #958
#854 may also be resolved by this

• Updated filter_pre_get_avatar_data_url so it passes the requested width and height arguments to get_the_post_thumbnail_url
  • Ensures the requested avatar size ( or the closest your particular combination of theme and hosting environment can produce ) is applied to a guest author's feature image.
• Updated filter_pre_get_avatar_data_url so it passes the same arguments it received when recursively calling get_avatar_url
  • Ensures the requested avatar size is applied to Gravatar images rather than reverting to the default.

Steps to Test

• Add the Post Author block to a post or template.
  • Any changes to the Avatar Size should be reflected in the rendered content.
• Inspect the response to a request for /wp-json/wp/v2/users/:user-id/ from the block editor.
  • The URLs in the avatar_urls object should match their associated keys. For example the default sizes: 24, 48, 96
• Inspect the response to a request for /wp-json/coauthors/v1/authors/:post-id/ from the block editor.
  • For authors using gravatar, the avatar should use the default size of 96px.
  • For guest authors using a feature image, the value should use the closest available size to 96px.
• Inspect the classic editor coauthor meta box.
  • For authors using gravatar, the avatar should use the default size of 96px.
  • For guest authors using a feature image, the value should use the closest available size to 96px.
• Use your browser's dev tools to turn off JavaScript and open a post in the classic editor.
  • The coauthor avatars in #coauthors-readonly should be constrained to 25px through CSS.

[douglas-johnson]

@GaryJones I updated this pull request to remove var $gravatar_size as discussed in #958 . The desciption and testing steps have been updated accordingly.