Add optional cache viewer resource to core implementation

Adds an endpoint to view cache layer and reset keys manually. New request filter added to enable optional paths (to turn on/off the resources), and add a special UUID key that is refreshed on application start. This key is used to secure the cache endpoint that may have sensitive data in the keys when there may not be authentication present.

core/src/main/java/org/eclipsefoundation/core/model/StartupProxy.java

@@ -9,7 +9,7 @@
 *
 * SPDX-License-Identifier: EPL-2.0
 **********************************************************************/
-package org.eclipsefoundation.core.service;
+package org.eclipsefoundation.core.model;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;