Filings UI: remove service working temp plugin after Dec 2022

In ticket [10159](https://app.zenhub.com/workspaces/entities-team-space-6143567664fb320019b81f39/issues/bcgov/entity/10159), a temporary plugin was installed to remove any Progressive Web App / Service Worker that users may have on their system from a previous version of Filings UI (which was not behaving as we wanted).

This temporary plugin ([webpack-remove-serviceworker-plugin](https://www.npmjs.com/package/webpack-remove-serviceworker-plugin)) should remain in our production code for "some time" -- enough time for users to load the updated app and fix the service worker issue.

Hence, this ticket is to remove the package and config for this plugin **one year** after the original fix. There is no harm in leaving this plugin in place longer than a year; it's just cleanup.

**To do:
- [ ] delete ~/src/registerServiceWorker.ts
- [ ] uninstall webpack-remove-serviceworker-plugin dependency
- [ ] remove code from ~/vue.config.js