Discussion: Move all nginx-common components into main `nginx` package

Originated as part of a discussion in #23 - the fix for that bug will be limited to a single SystemD file change but the larger discussion of merging packages will remain here.

As part of a discussion to fix #23, it was discussed and mentioned that nginx-common does not serve a purpose anymore, and its components should be merged with the main nginx package and then eliminated.

Previously, this was done but was then reverted for various reasons.

This thread and issue here is to discuss the moving of nginx-common into nginx.

However, I think we should not rush hastily into this, this close to trixie and other milestones in Debian. Therefore, we should discuss this thoroughly and identify any issues with regards to it. This includes identification of reverse-dependencies, etc. on nginx-common to make sure there's no fallout from its removal.