Debian/Ubuntu packaging

[dreibh]

Debian/Ubuntu packaging:

• Added Debian/Ubuntu packaging files (debian/ directory)
• Added scripts to create custom Debian/Ubuntu packages, by using pbuilder or Ubuntu Launchpad PPA upload (details in README.Debian).
• Added Linux Software Map (LSM) entry file.

[dreibh]

Note: The build fixes from https://github.com/p4lang/behavioral-model/pull/988 are necessary, in order to have all required files for a build in a "make dist" tarball!

[dreibh]

Built packages for Ubuntu Focal, Groovy and Hirsuite can be found in my Launchpad PPA: https://launchpad.net/~dreibh/+archive/ubuntu/ppa/+packages?field.name_filter=bm

I filed a Debian RFS for the packaging as well: https://mentors.debian.net/package/bm/

[github-actions[bot]]

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