htools: create InstanceStatus ADT
htools: create InstanceStatus ADT

Signed-off-by: Agata Murawska <4c8886dbe342c6966e25105100cfee09458faa93@google.com>
Reviewed-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>

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