feat: collect application metrics

[daniel-mader]

Description of change

Please write a summary of your changes and why you made them.

Links to any relevant issues

• n/a

How the change has been tested

Run UniCore locally, make calls to it using Postman.

Definition of Done checklist

Add an x to the boxes that are relevant to your changes.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[M-Adam-Hus]

feat: add /metrics and /health endpoints