Convert backend code to ES modules

Bundling code now with Rollup for its flat bundling and tree shaking
support. Front end code still goes through Webpack for browser support.

bin/genieacs-cwmp

@@ -1,20 +1,20 @@
-#!/usr/bin/env node
+#!/usr/bin/env -S node -r esm
 "use strict";
-const path = require("path");
-const fs = require("fs");
+import path from "path";
+import fs from "fs";
 
 process.chdir(path.resolve(path.dirname(fs.realpathSync(__filename)), ".."));
 
-const config = require("../lib/config");
-const logger = require("../lib/logger");
-const cluster = require("../lib/cluster");
-const server = require("../lib/server");
-const cwmp = require("../lib/cwmp");
-const db = require("../lib/db");
-const extensions = require("../lib/extensions");
-const cache = require("../lib/cache");
+import * as config from "../lib/config";
+import * as logger from "../lib/logger";
+import * as cluster from "../lib/cluster";
+import * as server from "../lib/server";
+import * as cwmp from "../lib/cwmp";
+import * as db from "../lib/db";
+import * as extensions from "../lib/extensions";
+import * as cache from "../lib/cache";
 
-const VERSION = require("../package.json").version;
+import { version as VERSION } from "../package.json";
 
 logger.init("cwmp", VERSION);