Systemd reapplies its known values on reload, so we cannot simply call
into PVE::CGroup. Call systemd's SetUnitProperties method via dbus
instead.
The hotplug and startup code also calculated different values, as one
operated within systemd's value framework (documented in
systemd.resource-control(5)) and one worked with cgroup values
(distinguishing between cgroup v1 and v2 manually).
This is now unified by overriding `change_cpu_quota()` and
`change_cpu_shares()` via `PVE::QemuServer::CGroup` which now takes
systemd-based values and sends those directly via dbus.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
