webpack v4 -> v5 polyfill configuration

From the error message that showed before these changes:

webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.

If you want to include a polyfill, you need to:
	- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
	- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
	resolve.fallback: { "buffer": false }

package.json

@@ -123,6 +123,7 @@
   },
   "devDependencies": {
     "@babel/eslint-parser": "^7.16.3",
+    "buffer": "^6.0.3",
     "bundlesize": "^0.18.1",
     "chai": "^4.1.2",
     "chai-http": "^4.0.0",

webpack.config.js

@@ -193,6 +193,7 @@ const generateConfig = ({extensionPath, devMode=false, customOutputPath, analyze
     resolve: {
       alias: aliasesToResolve,
       fallback: {
+        buffer: require.resolve("buffer/"),
         fs: false
       }
     },