Implement ReactJS into the project

[Xpirix]

• This small issue is a part of the main issue #319:

  • [x] Install Node.js and npm.
  • [x] Use create-react-app or a similar tool to set up React.

[Xpirix]

This has been implemented in the commit https://github.com/qgis/QGIS-Django/commit/f3bc3bf7ac61f5f831cbe923d84eab7e0bf9f7b7