F/ OS-387 add protocol version

[Rekard0]

Description

Please include a summary of the change and be sure you follow the contributions rules we do provide here

Task: OS-387

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• Any dependent changes have been merged and published in downstream modules.
• I ran all tests with success and extended them if necessary.
• I have updated the CHANGELOG.md file in the root folder.
• I have tested my code on the test network.

[heueristik]

I think we should include the protocolVersion function in every (most derived) protocol contract we maintain. I think it would be beneficial to incrementally add it to all framework contracts with every upgrade we must make.

In this protocol upgrade, I would add it to DAOFactory as well for convenience purposes (although DAOFactory has daoBase and we can, with more effort, get it also from there).

We should discuss why this is needed in a meeting.