Fixes #12216 - support http proxies for compute resources

Fixes #21015 - sync host and hostgroup rabl to show all_classes

Fixes #20516 - GET hosts API displays owner_name attribute

Fixes #20858 - pxe_loader in GET api/v2/hostgroups/:id

Fixes #20500 - Allow GET /api/hostgroups to include parameters

Add include Array parameter to GET /api/hostgroups v2 that will
optionally include a hostgroup's parameters when the include parameter
contains 'parameters'.

Fixes #20701 - Subnet6 fields info in GET api/v2/hostgroups/:id

Fixes #20711 - GET host interface API will show fqdn attribute

Fixes #17811 - Improve error message LDAP fail

Fixes #16112 - support for netgroups in LDAP auth source

Fixes #20072 - Allow thin host list via API