- updated manifests for context, device, service, slice to expose metrics endpoint

- Reduced log level of device, service and slice components to INFO

- updated component manifests to reduce CPU and Memory requests and limits

- tweaked resources and containers to accelerate tests

Context service:
- corrected port numbers

Device service:
- corrected port numbers
- upgraded gitlab-ci configuration

Preliminary unfinished version of device service and Context API based on Redis. To be finished, it is just a backup.

This reverts merge request !3