New option: Edit button

[ignaciogros]

• New preference in the "Share link" dialog: "Edit button".
• If it's checked and you go to that link, you'll see an "Edit content" button in the top bar. Clicking on it, you can edit the content in eXeLearning (static version).

[ignaciogros]

After testing with real content and reviewing the results, I believe it doesn’t make sense to include the edit button. Users will expect to be able to edit any content, which won’t be possible because many URLs will fail (e.g., Nextcloud, Google Drive) if the editor’s CORS proxy fails.

It will work perfectly for content from the same domain, but since any origin is allowed, CORS-related issues would be very common.