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/backend/.dockerignore

@@ -0,0 +1 @@
+node_modules

react-express-mongodb/backend/Dockerfile

@@ -1,27 +1,14 @@
-FROM node:13.13.0-stretch-slim
-
-#Argument that is passed from docer-compose.yaml file
-ARG NODE_PORT
-
-#Echo the argument to check passed argument loaded here correctly
-RUN echo "Argument port is : $NODE_PORT"
+FROM node:lts-buster-slim
 
 # Create app directory
 WORKDIR /usr/src/app
 
-#COPY . .
-COPY . .
+COPY package.json /usr/src/app/package.json
+COPY package-lock.json /usr/src/app/package-lock.json
+RUN npm ci
 
-# Install app dependencies
-# A wildcard is used to ensure both package.json AND package-lock.json are copied
-# where available (npm@5+)
-RUN npm install
-
-
-#In my case my app binds to port NODE_PORT so you'll use the EXPOSE instruction to have it mapped by the docker daemon:
-
-EXPOSE ${NODE_PORT}
-
-CMD npm run dev
+COPY . /usr/src/app
 
+EXPOSE 3000
 
+CMD [ "npm", "run", "dev" ]