Introduced a new Video model and integrated a ComboBox for video selection in the HtmlBox control. Updated the HtmlBox.cs to handle video selection and loaded videos dynamically.

Introduced a new Videos property in ListItem to handle a collection of videos. Updated SearchResultViewModel to set this property and modified SearchResult and HtmlBox views to bind and display these videos.

Renamed `Video` to `MediaVideo` and updated its properties. Adjusted references throughout the project, ensuring consistent naming and functionality improvements. Removed redundant trailer selection logic and optimized video processing in the SearchResultViewModel and HtmlBox components.

Removed the SetTrailer method from SearchResultViewModel as it was not being used. Also cleaned up unnecessary using statement in HtmlBox.xaml.cs.