controller: Populate image size in openstack image API
controller: Populate image size in openstack image API

This means that ciao-cli image list and ciao-cli image show gives the
image size in bytes.

Fixes: #959

Signed-off-by: Rob Bradford <c49e1dc14cd52e2644816db47123896e0ac79025@intel.com>

01org/ciao,matthewrsj/ciao,mcastelino/ciao,tpepper/ciao,tpepper/ciao,kaccardi/ciao,markdryan/ciao,mcastelino/ciao,obedmr/ciao,markdryan/ciao,obedmr/ciao,mrkz/ciao,mcastelino/ciao,rbradford/ciao,erick0z/ciao,wcwxyz/ciao,ciao-project/ciao,01org/ciao,tpepper/ciao,erick0z/ciao,rbradford/ciao,mrkz/ciao,erick0z/ciao,matthewrsj/ciao,matthewrsj/ciao,wcwxyz/ciao,ciao-project/ciao,obedmr/ciao,mrkz/ciao,kaccardi/ciao,wcwxyz/ciao