feat(ui): tidy up model manager styling

fixes #2970

invokeai/frontend/web/src/common/components/IAIForm.tsx

@@ -0,0 +1,8 @@
+import { chakra } from '@chakra-ui/react';
+
+/**
+ * Chakra-enabled <form />
+ */
+const IAIForm = chakra.form;
+
+export default IAIForm;