Has a developer I would like to create a contentset via aio cli

**Is your feature request related to a problem? Please describe.**
Currently with aio cli we can get or delete a contentset, but I don't see a way to create the content set with the command line

**Describe the solution you'd like**
As the API allow to create a contentset, it should be possible to implement it in the aio cli

**Describe alternatives you've considered**
I don't see any alternative.

**Additional context**
I need to create quickly a contentset based on some diff tool report in order to speed up what need to be re-sync.

Start by examining the existing aio CLI commands that get and delete contentsets, then compare them with the API's contentset creation operation. Done means the CLI can create a contentset from the information required by that API and supports the reported diff-tool workflow.

Written by the indexing model from the issue text.