Run docker containers as non-root

[petr-pokorny-absa]

This pull request introduces improvements to the Dockerfiles for both the backend and frontend services to enhance security and ensure proper file permissions. The main changes involve setting appropriate permissions for application files and directories, and running containers as non-root users.

Dockerfile changes for backend (Dockerfile):

• Set permissions: Changed permissions for /opt/app (755), status-board-assembly.jar (644), and entrypoint.sh (755) to ensure correct access rights.
• Non-root user: Configured the container to run as user 10001:10001 instead of root, improving security.

Dockerfile changes for frontend (UI.Dockerfile):

• Set permissions: Recursively set permissions (777) for /var/cache/nginx and /var/run to allow the nginx process to write to these directories.
• Non-root user: Configured the container to run as the nginx user, rather than root, for better security

Release notes:

• Changes docker images to run application as non-root

Closes: #25

[github-actions]

JaCoCo Coverage Report

Metric (instruction)	Coverage	Threshold	Status
Overall	80.51%	80.0%	✅
Changed Files	0.0%	80.0%	✅

Report	Coverage (O/Ch)	Threshold (O/Ch)	Status (O/Ch)
Report: root - scala:2.13.12	80.51% / 0.0%	80.0% / 80.0%	✅/✅

File Path	Coverage	Threshold	Status

No changed file in reports.

[oto-macenauer-absa]

lgtm