Move node polyfills in webpack config to 3rd party in preparation for webpack 5

Author: andriijas

packages/react-error-overlay/package.json

@@ -55,6 +55,7 @@
     "jest": "25.5.4",
     "jest-fetch-mock": "2.1.2",
     "object-assign": "4.1.1",
+    "path-browserify": "^1.0.1",
     "promise": "8.1.0",
     "raw-loader": "^3.1.0",
     "react": "^16.12.0",

packages/react-error-overlay/src/utils/unmapper.js

@@ -9,7 +9,7 @@
 import StackFrame from './stack-frame';
 import { getSourceMap } from './getSourceMap';
 import { getLinesAround } from './getLinesAround';
-import path from 'path';
+import path from 'path-browserify';
 
 function count(search: string, string: string): number {
   // Count starts at -1 because a do-while loop always runs at least once