feat(Google Vertex Chat Model Node): Add support for Google Vertex AI Chat models (#9970)

Co-authored-by: oleg <oleg@n8n.io>

packages/@n8n/nodes-langchain/nodes/llms/LmChatGoogleVertex/error-handling.ts

@@ -0,0 +1,25 @@
+export interface ErrorLike {
+	message?: string;
+	description?: string;
+}
+
+export interface ErrorContext {
+	modelName?: string;
+}
+
+export function makeErrorFromStatus(statusCode: number, context?: ErrorContext): ErrorLike {
+	const errorMessages: Record<number, ErrorLike> = {
+		403: {
+			message: 'Unauthorized for this project',
+			description:
+				'Check your Google Cloud project ID, and that your credential has access to that project',
+		},
+		404: {
+			message: context?.modelName
+				? `No model found called '${context.modelName}'`
+				: 'No model found',
+		},
+	};
+
+	return errorMessages[statusCode];
+}