- Fix version conversion for Debian policy compliance
(e.g., weekly-2025.01.28 -> 0~weekly.2025.01.28)
- Add MIME type registration for .fcstd files
- Add AppStream metainfo for software centers
- Add copyright file (required by Debian policy)
- Improve maintainer scripts with proper case statements
- Expand dependencies in control file (Depends/Recommends/Suggests)
- Add .deb build step to release workflow
- Simplify build workflow to let script handle version conversion
These files are not used in Debian or the PPA; they use conventions from
many years ago and in general are cruft. The canonical location for this
information is now https://salsa.debian.org/science-team/freecad. This
fixes#2984.