[slapos_hypermedia] Upgrade to new erp5_hal_json_style.

A few tests can be taken out of this BT to be put in erp5_hal_json_style.
[slapos_hypermedia] Add support for other types of users, like Computer Partition.
[slapos_hypermedia] Add Instance_getHateoasRelatedHostingSubscription.
slap: Add OpenOrder.getInformation() and OpenOrder.getOpenOrderList().
slapos CLI: add slapos list and slapos info.
[slapos_hypermedia] add hateoas URL preference.
[SlapTool] Add getHateoasUrl method.
slapos.slap: add getHateoasUrl support.
[slapos_erp5] testSlapOSERP5SkinSelection: add Hal skin.
[slapos.slap] Implement Partition.getInformation()