Add node-related workload
Add node-related workload

This patch further expands the workload by performing various node
operations.

Signed-off-by: Hrvoje Ribicic <be5828fca31f89218048bec4189e30a581aa65da@google.com>
Reviewed-by: Helga Velroyen <2d0126b1ec6f9ec5cbec4a7012aa14faeaef10f5@google.com>

bitemyapp/ganeti,apyrgio/ganeti,ganeti-github-testing/ganeti-test-1,ganeti-github-testing/ganeti-test-1,dimara/ganeti,mbakke/ganeti,apyrgio/ganeti,grnet/snf-ganeti,leshchevds/ganeti,grnet/snf-ganeti,yiannist/ganeti,leshchevds/ganeti,leshchevds/ganeti,ganeti/ganeti,andir/ganeti,dimara/ganeti,onponomarev/ganeti,andir/ganeti,yiannist/ganeti,ganeti/ganeti,yiannist/ganeti,bitemyapp/ganeti,andir/ganeti,mbakke/ganeti,ganeti/ganeti,mbakke/ganeti,onponomarev/ganeti