N8N-4126 credentials injection and testing on specific nodes (#3816)

* Add credential injection and testing to Lemlist, Uproc, Supabase, Segment, Phantombuster, Mailgun and Dropcontact

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

@@ -1,4 +1,9 @@
-import { ICredentialType, NodePropertyTypes } from 'n8n-workflow';
+import {
+	IAuthenticateGeneric,
+	ICredentialTestRequest,
+	ICredentialType,
+	NodePropertyTypes,
+} from 'n8n-workflow';
 
 export class DropcontactApi implements ICredentialType {
 	name = 'dropcontactApi';
@@ -12,4 +17,23 @@ export class DropcontactApi implements ICredentialType {
 			default: '',
 		},
 	];
+	authenticate: IAuthenticateGeneric = {
+		type: 'generic',
+		properties: {
+			headers: {
+				'user-agent': 'n8n',
+				'X-Access-Token': '={{$credentials.apiKey}}',
+			},
+		},
+	};
+	test: ICredentialTestRequest = {
+		request: {
+			baseURL: 'https://api.dropcontact.io',
+			url: '/batch',
+			method: 'POST',
+			body: {
+				data: [{ email: '' }],
+			},
+		},
+	};
 }