Add media (URL): Validation needed for unsupported URLs like YouTube

[maurofmferrao]

When adding a YouTube link via the Add Media (URL) form, an Unexpected Error, please contact support. message appears. This happens because YouTube URLs are not supported as media, leading to a null value being passed in Library.php on line 2526.

Xibo\Factory\ModuleFactory::getByExtension(): Argument #1 ($extension) must be of type string, null given, called in /var/www/cms/lib/Controller/Library.php on line 2526

Steps to reproduce:

• Attempt to add a YouTube URL in the Add Media (URL) form.
• Observe the error message in log

Proposed solution:

• Add Validation: Prevent unsupported URLs (like YouTube) from being submitted in the form.
• Clearer Error Message: Display a specific message when an unsupported media type is added.