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/Requests/DeleteItemsRequest.php

@@ -28,15 +28,15 @@ class DeleteItemsRequest extends FormRequest
     {
         return [
             'ids' => [
-                'required'
+                'required',
             ],
             'ids.*' => [
                 'required',
                 Rule::exists('items', 'id'),
                 new RelationNotExist(Item::class, 'invoiceItems'),
                 new RelationNotExist(Item::class, 'estimateItems'),
-                new RelationNotExist(Item::class, 'taxes')
-            ]
+                new RelationNotExist(Item::class, 'taxes'),
+            ],
         ];
     }
 }