Enqueued_Scripts_Size_Check includes script dependencies

[jjgrainger]

The Enqueued_Scripts_Size_Check only accounts for scripts registered by the plugin that include the plugins URL in the script. There may be cases where a script requires a dependency that is sources outside of plugin directory, such as jQuery.

The Enqueued_Scripts_Size_Check should be updated to account for those external dependencies as part of the total script size for a page load.

Acceptance Criteria

• Update the Enqueued_Scripts_Size_Check class to account for external dependencies.
• Dependencies will be determined for a script using the WP_Scripts class.
• The dependency sizes will be stored separately from the plugin scripts sizes to help with reporting.
• Check error message will have detailed reporting highlighting.
  • The total script size enqueued for the page, including plugin scripts and inline scripts
  • The total size of script dependencies.
  • For example - "The total size of scripts enqueued for the page are X with dependencies adding X"

[swissspidy]

This will require some logic similar to load_script_textdomain to get the file path from the script URL.

Might be easiest to first converge this class with Enqueued_Styles_Size_Check (e.g. by adding an abstract class or trait) so this logic can be reused.