Refactor: remove FormatObjectList dependency and update logic locally for PHP 8 compatibility (#8207)

Author: jonwaldstein

composer.json

@@ -9,7 +9,6 @@
         "tecnickcom/tcpdf": "^6.2",
         "stripe/stripe-php": "^7.97.0",
         "paypal/paypal-checkout-sdk": "^1.0",
-        "kjohnson/format-object-list": "^0.1.0",
         "symfony/http-foundation": "v5.4.50",
         "stellarwp/field-conditions": "^1.1",
         "stellarwp/validation": "1.5.0",