Add deb package target and workflow

[gastmaier]

Generate a deb package, as we already do with libiio.

It is a copy from how libiio generates the deb package, with updated dependencies and a special case for GtkDataBox [1]. It should support Ubuntu version >= 20.04 .

I did not really like libiio's way of generating the debs/rpms, but for cohesion I used the same script. That being said, I don't think we should ever enable DEB_DETECT_DEPENDENCIES to auto-detect dependencies versions.

The CI is missing, but will probably be very similar to the one in libiio.

[1] In #404 it was suggested to generate debs for the Gtk2 version, but that means to branch from a old commit and create a "legacy" release; instead, I bundled it (140kB) in the deb/rpm (all of its deps are covered by IIO-Oscilloscope dependencies).

Suggestions are welcome.

[gastmaier]

I included the CI with commit 2ed30f7, however libad*-iio is not included in the main Ubuntus repo. I was thinking to bundle with iio-osc, instead of making the user install 2 more packages.

Edit: I bundled libad*-iio with f44b844, see run 4493892579. I still need to test the deb in a fresh container.

[gastmaier]

Summary of the rebase (5 days ago):

• Supports Ubuntu 22.04 (v0.15); for Ubuntu 20.04 (v0.14), there is branch ubuntu20.04-v0.14.
• Uses only packages from the main Ubuntu repository as dependencies.
• Checks if libad9361 or libad9166 is included, but since only libad9361 is available in the main Ubuntu repository, it is not compiled with libad9166 support.

[gastmaier]

Requires changes to meet new apt repo requirements + wait pkg deps (*-dev) to be stable in the apt.