Fetch NEVRA from our DB instead of `pulp` in `release_planner.py`

[anfimovdm]

We're planning to adjust BuildTaskArtifact model with metadata field where there would be NEVRA for sure and maybe later other data (such as checksums, etc.). After adjusting that model, we need to make some adjustments in release_planner.py to get NEVRA from our DB instead of pulp.

Depends on https://github.com/AlmaLinux/albs-web-server/pull/1082