Abhishek Kumar 88337bdea4
server: fix finding pools for volume migration (#4693)
While finding pools for volume migration list following compatible storages:
- all zone-wide storages of the same hypervisor.
- when the volume is attached to a VM, then all storages from the same cluster as that of VM.
- for detached volume, all storages that belong to clusters of the same hypervisor. 

Fixes #4692 
Fixes #4400
2021-02-25 22:13:50 +05:30
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