Tidy up RdCore Installation with docker

[akoharu]

This PR is to tidy up the docker files and make them easier to maintain.
The previous docker setup makes duplicate copies of the code and is not easy to maintain.

This PR will:

• Move the docker-compose files to the root of the project
• rename the Dockerfile-build-radiusdesk to Dockerfile and move it to the root of the project
• rename the local_build.sh to docker_build.sh and move it to the root of the project
• update the docker_build.sh to match with the new project structure

Testing

• Run the docker_build.sh script
• Access the radiusdesk web interface