Support "--software-*" flags in our Open Source artifact generators

Acceptance criteria:

• All Update Module Artifact generators in mender/support/modules-artifact-gen are updated to directly support these options:
  • --software-version
  • --software-name
  • --software-filesystem

The arguments are indirectly supported by using '--' syntax to pass them directly to mender-artifact, but since these are likely to be used a lot, they should be first class citizens.

Feature branch name: feature/partial_updates