[CI] Online software builds

Do not merge

This purely technical MR aims to produce firmware artifacts for all firmware flavors when committing to the online-software-ci branch.

The Hog framework specifies a few cases in which the CI is triggered. Merging into the devel branch (i.e. intermediate branch) is not part of those, so let's play a trick with branches. The additional online-software-ci exists for multiple reasons:

• Escape the protections (rightfully) set on devel
• Allow producing all artifacts needed for a given online software release, independently of the firmware development status
• Do not prevent parallel MR from devel to master

Push the commit for which you need firmware artifacts here and select the firmware flavors you need in the triggered CI pipeline. Works only for commits with master as a parent.