[Frontend] Added frontend directory with the boilerplate layout

[Sanskar95]

No description provided.

[Sanskar95]

@iskitsas

[Sanskar95]

This PR contains the following:
Boilerplate code with nav bar and side menu.
Single test case usinreact-testing-library
React Router implemened in side menu

Sample UI deployment: https://cms-frontend-webapp.herokuapp.com/

[iskitsas]

Hi @Sanskar95 ,

In order to merge a PR related with a new feature it most cover a minimal set of requirements, to be fully implemented.
You can work on this branch, and when you have something ready, to ask for a full review. A README.md with full instruction of how someone cat test or work with it locally, is also essential.

So, before starting any implementation, define what exactly you are going to implement, and keep the tasks small. We prefer the agile approach.

For example you can start with a minimum set of some menus, which also demonstrate the integration with the CMS. A first good example is the about page, with information about the running versions, of the server and the frontend.