fix: Fix format check in test package

feat: Add 406 mapper

Resolves #66 (closed)

core/src/main/java/org/eclipsefoundation/core/resource/mapper/NotAcceptableMapper.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.core.resource.mapper;
+
+import javax.ws.rs.NotAcceptableException;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.Response.Status;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+
+import org.eclipsefoundation.core.model.Error;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Provider
+public class NotAcceptableMapper implements ExceptionMapper<NotAcceptableException> {
+    private static final Logger LOGGER = LoggerFactory.getLogger(NotAcceptableMapper.class);
+
+    @Override
+    public Response toResponse(NotAcceptableException exception) {
+        LOGGER.error(exception.getMessage(), exception);
+        return new Error(Status.NOT_ACCEPTABLE, "Could not process the given request: " + exception.getMessage())
+                .asResponse();
+    }
+}
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