- added npm package dotenv-webpack for using env variables on clientside

- added API File Controller for downloading files e.g. /api/download/1022
- also create has codes by submitting new dataset
- added edit dataset functionalities for role submitter
- added the following route for role submitter: /dataset/:id/update', 'DatasetController.update'
- created extra UpdateDatasetValidator.ts for validating updated dataset
- npm updates

webpack.config.js

@@ -1,6 +1,17 @@
 const { join, resolve, dirname } = require('path');
 const Encore = require('@symfony/webpack-encore');
 const { VueLoaderPlugin } = require('vue-loader');
+const dotenv = require('dotenv-webpack');
+
+// Load the environment variables from the.env file
+Encore.addPlugin(
+    new dotenv({
+      path: ".env",
+      defaults: ".env",
+      systemvars: true,
+      allowEmptyValues: true,
+    })
+  )
 
 const babelLoader = {
     // test: /\.js$/,