api: allow to clear vmstate actively

api: allow to clear vmstate actively

Sometimes, a user wants to remove the 'suspended' state without
resuming the vm from that state. Since the vm is locked with
'suspended', this was not possible without help from root@pam

This patch allows to delete the vmstate and the suspended lock and
related config entries with it. The user still has to have the right
priviliges and the vm cannot be 'protected' for this to work

Inspired-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>