Proposal PR: Userspace Convertor: Add Deduplication Version Support

[estebanreyl]

Introduce a simple versioning system for the userspace convertor deduplication dbs. This prevents inconsistencies with an existing DB if a new version is used.

What this PR does / why we need it:
This is a proposal PR on how to handle versioning for the layer/manifest deduplication going forward. It is not done as is since we still need some way of finding the version of the overlaybd tools to combine with the local deduplication versions. I furthermore propose that major versions for the tools denote a break in the digest outputs. I also updated the sample workload file to include more info and validation as well as added some unit tests. We can probably incorparete that with the tests but tbh I am unclear on how at the moment.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #250

Please check the following list:

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?