Even though a gr-list-view element has been established for many of the
common list view functions, The tables themselves are still
generated by the parent element and passed as <content>. There were
many common functions used in the table generation itself.
Break out those common functions into a behavior, and implement in
gr-admin-group-list and gr-admin-project list. This will be used in
further admin pages as well.
Change-Id: I60227b8c30ac18176bbf923ee1fb02bdd985e5c3
e00d1eeede