webadmin: Disks VMs Templates sub-tabs resizable columns

VMs/Templates sub-tabs under Disks main-tab
now support resizable columns.

* Invoked enableColumnResizing() on each sub-tab.
* Added a static width value for each column.

Change-Id: Ic7db506c95ec3642d7247f64b632e6ec7333d94f
Signed-off-by: Daniel Erez <derez@redhat.com>