chore(lambda): add toString to lambda architecture (#26145)

Add  toString to Lambda Architecture property

When throwing errors during synthesis, you can't see the architecture chosen for a lambda. Adding this toString method solves that

Closes #26117

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/aws-lambda/lib/architecture.ts

@@ -36,4 +36,11 @@ export class Architecture {
     this.name = archName;
     this.dockerPlatform = dockerPlatform;
   }
+
+  /**
+  * Returns a string representation of the architecture using the name
+  */
+  public toString(): string {
+    return this.name;
+  }
 }

packages/aws-cdk-lib/aws-lambda/test/architecture.test.ts

@@ -0,0 +1,21 @@
+
+import { App, Stack } from '../../core';
+import * as lambda from '../lib';
+
+describe('architecture', () => {
+  const app = new App();
+  const stack = new Stack(app, 'stack');
+
+  test('toString to return the architecture name', () => {
+    // GIVEN
+    const testLambda = new lambda.Function(stack, 'testLambda', {
+      code: new lambda.InlineCode('foo'),
+      handler: 'index.handler',
+      runtime: lambda.Runtime.NODEJS_14_X,
+    },
+    );
+
+    // THEN
+    expect(`${testLambda.architecture}`).toEqual(testLambda.architecture.name);
+  });
+});