[FIX] web_editor: show toaster notification error on uploading folder

Steps to reproduce:

OS: Ubuntu 20.04.4 LTS with nautilus
Browser: Google Chrome Version 123.0.6312.58

- type /file command in knowledge
- select a folder and click on open
- traceback occurs

Before this commit:

When a user attempts to upload a folder using /file command, the
processing begins, but the folder is not actually uploaded because the
`getDataURLFromFile` return promise which is not fulfiled. Additionally,
there is no indication of any warnings or errors during the folder
upload process.

After this commit:

If a user attempts to upload a folder instead of a file using the /file
command, it results in a error message in toaster notification.

task-3690847

closes #159755

X-original-commit: 0b27ac0
Signed-off-by: Damien Abeloos (abd) <abd@odoo.com>

addons/web_editor/i18n/web_editor.pot

@@ -871,6 +871,12 @@ msgstr ""
 msgid "Could not install module %s"
 msgstr ""
 
+#. module: web_editor
+#. odoo-javascript
+#: code:addons/web_editor/static/src/components/upload_progress_toast/upload_service.js:0
+#, python-format
+msgid "Could not load the file \"%s\"."
+
 #. module: web_editor
 #: model_terms:ir.ui.view,arch_db:web_editor.snippet_options_background_options
 msgid "Cover"

addons/web_editor/static/src/components/upload_progress_toast/upload_service.js

@@ -2,9 +2,11 @@
 
 import { registry } from '@web/core/registry';
 import { UploadProgressToast } from './upload_progress_toast';
+import { _t } from "@web/core/l10n/translation";
 import { checkFileSize } from "@web/core/utils/files";
 import { humanNumber } from "@web/core/utils/numbers";
 import { getDataURLFromFile } from "@web/core/utils/urls";
+import { sprintf } from "@web/core/utils/strings";
 import { reactive } from "@odoo/owl";
 
 export const AUTOCLOSE_DELAY = 3000;
@@ -94,7 +96,20 @@ export const uploadService = {
                 // limited by bandwidth.
                 for (const sortedFile of sortedFiles) {
                     const file = progressToast.files[sortedFile.progressToastId];
-                    const dataURL = await getDataURLFromFile(sortedFile);
+                    let dataURL;
+                    try {
+                        dataURL = await getDataURLFromFile(sortedFile);
+                    } catch {
+                        deleteFile(file.id);
+                        env.services.notification.add(
+                            sprintf(
+                                _t('Could not load the file "%s".'),
+                                sortedFile.name
+                            ),
+                            { type: 'danger' }
+                        );
+                        continue
+                    }
                     try {
                         const xhr = new XMLHttpRequest();
                         xhr.upload.addEventListener('progress', ev => {