* fix: new button remove node

check if the node have active machines, is localhost or have bases
if true, add a var to the list
the value of this var is shown in the template to disabled the button

closes #870

* feat: new button remove node

new remove button on node list
check if the node have active machines, is localhost or has bases
if true, add a var to the list
the value of this var is shown in the template to disabled the remove button
otherwise action call to function  remove_node and delete the node from vms table

fixes #870

* feat: new button remove node

Check it for uninitialized values when evaluate if a node can be remove.
Added bv.enabled=1 into _list_bases_vm for prevent a bug when a base is created in remote and then removed in list_bases.

fixes #870