fix(seven Node): Rename sms77 to seven, fix credentials test (#7180)

Github issue / Community forum post (link here to close automatically):

packages/nodes-base/credentials/Sms77Api.credentials.ts

@@ -8,7 +8,8 @@ import type {
 export class Sms77Api implements ICredentialType {
 	name = 'sms77Api';
 
-	displayName = 'Sms77 API';
+	// eslint-disable-next-line n8n-nodes-base/cred-class-field-display-name-miscased
+	displayName = 'seven API';
 
 	documentationUrl = 'sms77';
 
@@ -33,8 +34,21 @@ export class Sms77Api implements ICredentialType {
 
 	test: ICredentialTestRequest = {
 		request: {
-			baseURL: 'https://gateway.sms77.io/api',
-			url: '/balance',
+			baseURL: 'https://gateway.seven.io/api',
+			url: '/hooks',
+			qs: {
+				action: 'read',
+			},
 		},
+		rules: [
+			{
+				type: 'responseSuccessBody',
+				properties: {
+					key: 'success',
+					message: 'Invalid API Key',
+					value: undefined,
+				},
+			},
+		],
 	};
 }