Frontend development flow improvements - live reloading on local AEM instance

**Real time updates on author instance**

Currently to speed up styling a separate dev server is used (styling is done on static html file that is downloaded from AEM). This does not require local AEM instance to be running but on the other hand requires some additional work to get the actual AEM page HTML to work with.

Proposed improvement:
Allow to perform styling directly on local AEM page in the same manner as it's done on local dev server
Development flow:
1. Run author instance locally
2. Run `npm run start:withAem`
3. Open page to style on local aem instance, for example `/content/mysite/en.html`
3. Any change in css/js file will generate clientlibs, sync them into an AEM instance and refresh `/content/mysite/en.html` in browser.

Start with the existing local development flow invoked by `npm run start:withAem`, and trace how CSS/JS changes currently generate clientlibs and sync them to AEM. Done means styling an author page such as `/content/mysite/en.html` directly, with CSS/JS changes synchronized to the local AEM instance and the page refreshed automatically.

Written by the indexing model from the issue text.