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

app/Http/Controllers/V1/General/DateFormatsController.php

@@ -17,7 +17,7 @@ class DateFormatsController extends Controller
     public function __invoke(Request $request)
     {
         return response()->json([
-            'date_formats' => DateFormatter::get_list()
+            'date_formats' => DateFormatter::get_list(),
         ]);
     }
 }