Draft: feat: Add Drupal OAuth2 support into new efservices module

Resolves #35 (closed)

efservices/src/main/java/org/eclipsefoundation/efservices/api/DrupalOAuthAPI.java

+/*********************************************************************
+* Copyright (c) 2023 Eclipse Foundation.
+*
+* This program and the accompanying materials are made
+* available under the terms of the Eclipse Public License 2.0
+* which is available at https://www.eclipse.org/legal/epl-2.0/
+*
+* Author: Zachary Sabourin <zachary.sabourin@eclipse-foundation.org>
+*
+* SPDX-License-Identifier: EPL-2.0
+**********************************************************************/
+package org.eclipsefoundation.efservices.api;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+
+import org.eclipse.microprofile.rest.client.inject.RegisterRestClient;
+import org.eclipsefoundation.efservices.models.DrupalOAuthData;
+
+/**
+ * Drupal OAuth2 token validation API binding
+ */
+@Path("oauth2/tokens")
+@Produces(MediaType.APPLICATION_JSON)
+@RegisterRestClient(configKey = "accounts-api")
+public interface DrupalOAuthAPI {
+
+    @GET
+    @Path("{token}")
+    DrupalOAuthData getTokenInfo(@PathParam("token") String token);
+}