Putting two ends together

There are two parts that we need to connect between the frontend and the backend. The first part is the build process. Currently, we need to use mvn and npm to build the two parts separately. Once they are connected, we will only need to execute a single command to build the entire application.

The second part is to bridge the communication between the frontend and the backend. As mentioned, during development, the frontend will be served by webpack-dev-server under a different port than the one of the backend. Currently, both ends use the same port, 8080. We will need to change the port of the frontend to 3000 so that we can have both ends up and running at the same time. When our application is served from http://localhost:3000, the requests that the frontend pages send to the backend at http://localhost:8080, by default, will be blocked by the browser because they are cross-origin. The frontend won't be able to access the response of those requests unless we bridge...