Merge branch '1234-personform-does-not-work-in-create-mode' into 'master'

Resolve "PersonForm does not work in create mode"

Closes #1234

See merge request !1745

aleksis/core/frontend/components/person/PersonListWrapper.vue

@@ -17,6 +17,7 @@ export default {
       return this.$route.query._ui_action === "create"
         ? {
             fallbackUrl: { name: "core.persons" },
+            isCreate: true,
           }
         : {};
     },

aleksis/core/frontend/mixins/objectFormPropsMixin.js

@@ -51,7 +51,7 @@ export default {
     defaultItem: {
       type: Object,
       required: false,
-      default: null,
+      default: () => ({}),
     },
     /**
      * Item offered for editing if isCreate is false