Rootless Debian and Alpine Docker images by default

[joseluisq]

Description

This PR makes the current Debian and Alpine Docker images rootless by default using a dedicated user and group. This reduces the attack surface and improves security.

Remember: users can still run the containers as root if they explicitly set the user to root when running the container, e.g., using the --user root flag with docker run.

The static-web-server binary and all files in the /home/sws (home directory) are owned by the non-root user/group called sws, and the current working directory is the home directory.

For convenience, those paths are also available:

• Public directory: /home/sws/public
• Public directory symlink: /var/public -> /home/sws/public

Related Issue

Motivation and Context

Reduce the attack surface and enhance the security of existing Docker images.

How Has This Been Tested?

Screenshots (if appropriate):

[semanticdiff-com]

Review changes with