ui: tape: add form fields

this includes selectors for
* Allocation Policy
* Retention Policy
* Drives
* Changers
* Tape Device Paths
* Pools

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

www/tape/form/DriveSelector.js

@@ -0,0 +1,66 @@
+Ext.define('PBS.form.DriveSelector', {
+    extend: 'Proxmox.form.ComboGrid',
+    alias: 'widget.pbsDriveSelector',
+
+    allowBlank: false,
+    displayField: 'name',
+    valueField: 'name',
+    value: null,
+
+    store: {
+	proxy: {
+	    type: 'proxmox',
+	    url: '/api2/json/tape/drive',
+	},
+	autoLoad: true,
+	sorters: 'name',
+    },
+
+    listConfig: {
+	columns: [
+	    {
+		text: gettext('Name'),
+		dataIndex: 'name',
+		sortable: true,
+		flex: 1,
+		renderer: Ext.String.htmlEncode,
+	    },
+	    {
+		text: gettext('Vendor'),
+		dataIndex: 'vendor',
+		sortable: true,
+		flex: 1,
+		renderer: Ext.String.htmlEncode,
+	    },
+	    {
+		text: gettext('Model'),
+		dataIndex: 'model',
+		sortable: true,
+		flex: 1,
+		renderer: Ext.String.htmlEncode,
+	    },
+	    {
+		text: gettext('Serial'),
+		dataIndex: 'serial',
+		sortable: true,
+		flex: 1,
+		renderer: Ext.String.htmlEncode,
+	    },
+	],
+    },
+
+    initComponent: function() {
+	let me = this;
+
+	if (me.changer) {
+	    me.store.proxy.extraParams = {
+		changer: me.changer,
+	    };
+	} else {
+	    me.store.proxy.extraParams = {};
+	}
+
+	me.callParent();
+    },
+});
+