ui: add browser settings window

mostly copied from pve (for now; will refactor when i add it to
pmg too (soon)) without the pve specific features like dashboard
storages

contains some eslint fixes comparing to pves window

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

www/MainView.js

@@ -230,6 +230,11 @@ Ext.define('PBS.MainView', {
 		    margin: '0 5 0 0',
 		    iconCls: 'fa fa-user',
 		    menu: [
+			{
+			    iconCls: 'fa fa-gear',
+			    text: gettext('My Settings'),
+			    handler: () => Ext.create('PBS.window.Settings').show(),
+			},
 			{
 			    iconCls: 'fa fa-language',
 			    text: gettext('Language'),