mgr/dashboard: multisite sync policy improvements

mgr/dashboard: multisite sync policy improvements

https://tracker.ceph.com/issues/68097

Changes for this PR includes:
1) Populating the destination zones select option with a set of options to choose from, for flow and pipe so that user can't enter any invalid zone name
2) Provided zone option as 'All Zones (*)' in pipe, if user want to select all zones for source and destination zones
3) We are hiding the UniqueId column on sync policy table as we do not want to show it as this column is introduced just to uniquely identify a row in the table and should not be displayed to users as it is part of the internal logic to work.

Signed-off-by: Naman Munet <nmunet@redhat.com>