Implement PHP CS Fixer and a coding standard to follow (#471)

* Create PHP CS Fixer config and add to CI workflow

* Run php cs fixer on project

* Add newline at end of file

* Update to use PHP CS Fixer v3

* Run v3 config on project

* Run seperate config in CI

.github/workflows/ci.yaml

@@ -30,5 +30,8 @@ jobs:
       run: composer update --ignore-platform-req=php --no-interaction --no-progress
       if: "matrix.php >= 8"
 
+    - name: Check coding style
+      run: ./vendor/bin/php-cs-fixer fix -v --dry-run --using-cache=no --config=.php-cs-fixer.ci.php
+
     - name: Unit Tests
       run: php ./vendor/bin/pest