Add fallback dummy nodejs path module

The path is required in css module which we use for parsing
custom css string in the form editor.
We don't use functionality which is dependent on nodejs path module
so we can use "dummy" module. Alternatively we could install a polyfill for brower
for the path module but it would increase a package size with functions we don't use.
[MAILPOET-3214]

webpack.config.js

@@ -43,6 +43,7 @@ const baseConfig = {
     ],
     fallback: {
       fs: false,
+      path: false, // path is used in css module, but we don't use the functionality which requires it
     },
     extensions: ['.js', '.jsx', '.ts', '.tsx'],
     alias: {