CLOUDSTACK: 4705 - Fixed memory limits - domain limits test cases. Fixed attribute error

Signed-off-by: venkataswamybabu budumuru <venkataswamybabu.budumuru@citrix.com>
(cherry picked from commit 7854dbc2134a285c2f81b80cf8dfa3047ade50e5)
CLOUDSTACK-4747: Rename testcase name to use lesser characters

Renamed testcase name and also initialised _cleanup so that
it does not break on non-NS Cloudstack setup.

Signed-off-by: venkataswamybabu budumuru <venkataswamybabu.budumuru@citrix.com>
CLOUDSTACK-4682: VMs are getting deployed with shared service offering and local compute offering
VM deployment is fine, issue is in attach volume where all possible scenarios are not handled.
The following needs to be logic of attached volume:
1. if data volume scope is zone then allow attach (this is already there)
2. if data volume scope is cluster
   a. if root volume scope is host, allow if both are in same cluster (already there)
   b. if root volume scope is zone, allow if vm and data volume in same cluster (fixed as part of this commit)
3. if data volume scope is host allow if vm and data volume in same host (fixed as part of this commit)
CLOUDSTACK-4551: Migrating the data volume from NFS to local storage ,underlying disk offering is not changed.
Even though the volume may get migrated from shared to local storage, it is not possible to update the disk offering.
The fix is to disallow migration from shared to local store.