* Improve code style and PSR-12 compliance
- refactored code formatting to adhere to PSR-12 guidelines
- standardized coding conventions across the codebase
- added missing framework files and reverted markup changes
- reformatted arrays for enhanced readability
- updated language files for consistent styling and clarity
- minor miscellaneous improvements
- when the payments array was folded into sale_data there was an earlier payments[] reference in the foreach loop that didn't get folded in.
- Update PHPdoc
- Added ::class to remove polymorphic call warning
- Removed unreachable 'break;' statement after return statement.
- Added missing return type
- fixed missing assignment of mailchimp_api_key
