react-express-mongodb: clean frontend code

- apply prettier style on every js file
- remove mutation on immutable variables
- remove wrapper on top of axios
- fix form handling
- remove useless port definition in dockerfile

Signed-off-by: Jérémie Drouet <jeremie.drouet@gmail.com>

react-express-mongodb/frontend/Dockerfile

@@ -1,15 +1,9 @@
 # Create image based on the official Node image from dockerhub
-FROM node:13.13.0-stretch
-
-#Argument that is passed from docer-compose.yaml file
-ARG FRONT_END_PORT
+FROM node:lts-buster-slim
 
 # Create app directory
 WORKDIR /usr/src/app
 
-#Echo the argument to check passed argument loaded here correctly
-RUN echo "Argument port is : $FRONT_END_PORT"
-
 # Copy dependency definitions
 COPY package.json /usr/src/app
 COPY package-lock.json /usr/src/app
@@ -24,7 +18,7 @@ RUN npm ci
 COPY . /usr/src/app
 
 # Expose the port the app runs in
-EXPOSE ${FRONT_END_PORT}
+EXPOSE 3000
 
 # Serve the app
 CMD ["npm", "start"]