mkcloud: Add 9p fs for local repos to admin node

Add $localreposdir_src var and if available add 9p filesystem to admin node
so in the future local repositories can be used for the admin node.
This is still WIP but with this commit at least the 9p fs is available
in the VM and the var $localreposdir_target is exported for
the sshrun of qa_crowbarsetup.sh.
qa_crowbarsetup: Support cinder volume type select

Add 2 more variables to support cinder volume type selection.
$cinder_conf_volume_type indicates the type (e.g. local or netapp) and
$cinder_conf_volume_params can contain some configuration
parameters. E.g. to configure netapp, the variable could look like this:

storage_family 'ontap_7mode'
storage_protocol 'iscsi'
nfs_shares ''
vserver ''
netapp_server_hostname '192.168.124.11'
netapp_server_port 443
netapp_login 'admin'
netapp_password ''
netapp_vfiler ''
netapp_transport_type 'https'
netapp_volume_list ''
mkcloud: Also undefine virsh net and nodes

Networks and nodes are no longer transient so both must be undefined.
mkcloud: remove unused 'tempest' target

`./mkcloud tempest` isn't being used and it's completely broken, to run
tempest the way to go is `./mkcloud testsetup`.