api2/admin/datastore/pxar_file_download: download directory as zip

by using the new ZipEncoder and recursively add files to it
the zip only contains directories, normal files and hardlinks (by simply
copying the content), no symlinks, etc.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

www/window/FileBrowser.js

@@ -87,6 +87,9 @@ Ext.define("PBS.window.FileBrowser", {
 	    };
 	    params.filepath = data.filepath;
 	    atag.download = data.text;
+	    if (data.type === 'd') {
+		atag.download += ".zip";
+	    }
 	    atag.href = me
 	        .buildUrl(`/api2/json/admin/datastore/${view.datastore}/pxar-file-download`, params);
 	    atag.click();
@@ -106,6 +109,11 @@ Ext.define("PBS.window.FileBrowser", {
 		case 'f':
 		    canDownload = true;
 		    break;
+		case 'd':
+		    if (data.depth > 1) {
+			canDownload = true;
+		    }
+		    break;
 		default: break;
 	    }