webadmin: Render Networks main tab columns sortable

Rendered all columns sortable except for:
* Comment isn't helpful when it's displayed as icon.
* Role and Provider, don't currently support server-side sorting.

Change-Id: I440ad9be062547cdf4b1bad68d8f4d62072b5bef
Signed-off-by: Lior Vernia <lvernia@redhat.com>