Allow forms to have a file upload enctype

src/assets/views/utils/Form.svelte

@@ -14,6 +14,7 @@
     export let isBoldSubmit: boolean = true;
     export let resetButton: boolean = false;
     export let confirm: string = undefined;
+    export let withFiles: boolean = false;
 
     const formId = nextAvailableFormId++;
     setContext('formId', formId);
@@ -37,7 +38,7 @@
     }
 </style>
 
-<form {action} method="POST" id="{formId}-form" on:submit={handleSubmit}>
+<form {action} method="POST" id="{formId}-form" on:submit={handleSubmit} enctype={withFiles ? 'multipart/form-data' : undefined}>
     <CsrfTokenField/>
     <slot/>
     <div class="form-controls">