ui: acl: add improved permission selector

taken mostly from PVE, with adaption to how PBS does things.
Main difference is that we do not have a resource store singleton
here which we can use, but for datastores we can already use the
always present datastore-list store. Register it to the store manager
with a "storeId" property (vs. our internal storeid one).

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

www/NavigationTree.js

@@ -102,6 +102,7 @@ Ext.define('PBS.view.main.NavigationTree', {
 	    view.rstore = Ext.create('Proxmox.data.UpdateStore', {
 		autoStart: true,
 		interval: 15 * 1000,
+		storeId: 'pbs-datastore-list',
 		storeid: 'pbs-datastore-list',
 		model: 'pbs-datastore-list'
 	    });