Fix build issues (#104)

* fix linting issues on webpack.config.js

* sync with demo plugin, go mod tidy

* npm audit fix

There's a rash of lodash issues right now that have no available fix, but I'm fixing the remaining issues.

* use exact versions

* update webapp/package-lock.json too

* manually clean up go.mod/go.sum

* private package.json

webapp/babel.config.js

@@ -23,11 +23,13 @@ const config = {
             allExtensions: true,
             isTSX: true,
         }],
+        ['@emotion/babel-preset-css-prop'],
     ],
     plugins: [
         '@babel/plugin-proposal-class-properties',
         '@babel/plugin-syntax-dynamic-import',
         '@babel/proposal-object-rest-spread',
+        '@babel/plugin-proposal-optional-chaining',
         'babel-plugin-typescript-to-proptypes',
     ],
 };