fix #8015: ui: download url: let the user choose the .img image format

Like for the upload, '.raw' was appended to the name of '.img' images
downloaded as import content, which breaks importing images in other
formats, such as the qcow2 based Ubuntu cloud images.

After querying the URL of such an image, show a format selector and
append the extension of the selected format to the file name instead.

Signed-off-by: Michal Fox <me@dualfroz.com>
Link: https://lore.proxmox.com/20260929135840.2748665-3-me@dualfroz.com

www/manager6/window/DownloadUrlToStorage.js

@@ -30,6 +30,7 @@ Ext.define('PVE.window.DownloadUrlToStorage', {
             size: '-',
             mimetype: '-',
             enableQuery: true,
+            needsFormat: false,
         },
     },
 
@@ -82,6 +83,7 @@ Ext.define('PVE.window.DownloadUrlToStorage', {
 
                     let filename = data.filename || '';
                     let compression = '__default__';
+                    let needsFormat = false;
                     if (view.content === 'iso') {
                         const matches = filename.match(/^(.+)\.(gz|lzo|zst|bz2)$/i);
                         if (matches) {
@@ -89,10 +91,12 @@ Ext.define('PVE.window.DownloadUrlToStorage', {
                             compression = matches[2].toLowerCase();
                         }
                     } else if (view.content === 'import') {
-                        if (filename.endsWith('.img')) {
+                        // the extension does not tell the image format, the user has to select it
-                            filename += '.raw';
+                        needsFormat = filename.endsWith('.img');
-                        }
                     }
+                    me.queriedName = filename;
+                    me.getViewModel().set('needsFormat', needsFormat);
+                    me.lookup('imageFormat').setValue(null);
 
                     view.setValues({
                         filename,
@@ -106,6 +110,12 @@ Ext.define('PVE.window.DownloadUrlToStorage', {
             });
         },
 
+        formatChange: function (field, format) {
+            if (format) {
+                this.getView().setValues({ filename: `${this.queriedName}.${format}` });
+            }
+        },
+
         hashChange: function (field) {
             let checksum = Ext.getCmp('downloadUrlChecksum');
             if (field.getValue() === '__default__') {
@@ -169,6 +179,22 @@ Ext.define('PVE.window.DownloadUrlToStorage', {
                         return this.processRawValue(this.getRawValue())?.trim();
                     },
                 },
+                {
+                    xtype: 'pveDiskFormatSelector',
+                    reference: 'imageFormat',
+                    fieldLabel: gettext('Format'),
+                    submitValue: false,
+                    allowBlank: false,
+                    hidden: true,
+                    disabled: true,
+                    bind: {
+                        hidden: '{!needsFormat}',
+                        disabled: '{!needsFormat}',
+                    },
+                    listeners: {
+                        change: 'formatChange',
+                    },
+                },
             ],
             column1: [
                 {