dialog: improve error setting usability

Accept a RawError and create the error based on it instead.

src/lib/Dialog.svelte

@@ -4,7 +4,7 @@
 	 */
 	export interface DialogAPI {
 		/** shows an error message at the top of the dialog */
-		error: (message: ErrorMessage | null) => void;
+		error: (message: RawError | null) => void;
 		/** closes the dialog */
 		close: () => void;
 		/** opens the dialog */
@@ -54,7 +54,7 @@
 	import { flyAndScale } from './transition';
 	import Button from './Button.svelte';
 	import { X } from 'phosphor-svelte';
-	import { ErrorMessage } from './error';
+	import { ErrorMessage, type RawError } from './error';
 	import ErrorBox from './ErrorBox.svelte';
 
 	interface Props {
@@ -98,7 +98,7 @@
 	});
 
 	const dialogAPI: DialogAPI = {
-		error: (message) => (error = message),
+		error: (message) => (error = ErrorMessage.from(message)),
 		close: () => (open = false),
 		open: () => (open = true),
 		isOpen: () => open,