Continue work from
- https://lab.nexedi.com/nexedi/slapos.core/-/merge_requests/561
- https://lab.nexedi.com/nexedi/slapos.core/-/merge_requests/562
- https://lab.nexedi.com/romain/slapos.core/-/merge_requests/1
Rely on https://lab.nexedi.com/nexedi/erp5/-/merge_requests/2077
The goal is this MR is to introduce a more developper friendly API, based on JSON content exchange instead of the python xml marshaller.
SlapTool is not yet replaced on slap.py client side, as it requires missing migration compatibility code, and some scalability checks.