updatenotification: update_helper.js recode with pm2 library (v2.27.x) (#3332)

#3285

Because there is so many conflit with package,
I have rewrite the code with v2.27.0-develop

For remember:

 * recode: `update_helper.js` with `pm2` library
 * fix: default config -> `updates` is a array
 * delete: `command-exists` library (not used)
 * delete: `PM2_GetList()`  function (not used)
 * add: check `updates.length` (prevent crash)
 * add: `[PM2]` tag in log (for better visibility)
 * add: `pm2` library
 
advantage:
  * we use the pm2 library directly
* avoids weird returns from child_process.exec when requesting a json
format from pm2
  * simplified the code

inconvenient:
  * we have vulnerabilities with axios

240120 Fix:
* use `pm2_env.pm_cwd` instead of `pm2_env.PWD` : prevent using `pm2
restart <id> --update-env` in other directory (for enable GPU rendering
for exemple)
 * resolve packages (again)

modules/default/updatenotification/updatenotification.js

@@ -18,7 +18,7 @@ Module.register("updatenotification", {
 	suspended: false,
 	moduleList: {},
 	needRestart: false,
-	updates: {},
+	updates: [],
 
 	start () {
 		Log.info(`Starting module: ${this.name}`);