[core] cache: updated deprecated api of lru-cache, cleaned up mongodb capped collection and change stream related code

Author: Cihad Tekin

api/api.js

@@ -265,7 +265,7 @@ plugins.connectToAllDatabases().then(function() {
     if (cluster.isMaster) {
         plugins.installMissingPlugins(common.db);
         common.runners = require('./parts/jobs/runner');
-        common.cache = new CacheMaster(common.db);
+        common.cache = new CacheMaster();
         common.cache.start().then(() => {
             setImmediate(() => {
                 plugins.dispatch('/cache/init', {});
@@ -333,7 +333,7 @@ plugins.connectToAllDatabases().then(function() {
         console.log("Starting worker", process.pid, "parent:", process.ppid);
         const taskManager = require('./utils/taskmanager.js');
 
-        common.cache = new CacheWorker(common.db);
+        common.cache = new CacheWorker();
         common.cache.start();
 
         //since process restarted mark running tasks as errored