feat: horizontal checkboxes (#1911)

Adds the ability to have checkboxes align horizontally, wrapping when
they would go off the PDF

packages/ui/primitives/document-flow/field-item-advanced-settings.tsx

@@ -129,6 +129,7 @@ const getDefaultState = (fieldType: FieldType): FieldMeta => {
         validationLength: 0,
         required: false,
         readOnly: false,
+        direction: 'vertical',
       };
     case FieldType.DROPDOWN:
       return {