fixes #14041 - don't call select2 on CR form templates

select2 must be called only when the select becomes visible, not for
hidden template elements. add_child_node() already does when adding a
new set of fields from the template. without_select2 is removed from
all CR volume fields and a typo from ce59b508 fixed to ensure the first,
default volume initialises select2 when a CR is selected.

The interface_type_selected function is fixed to only call select2 on
its elements instead of the entire page, which also broke the volume
form templates if a NIC type was changed.