multimedia/*pipe-viewer: Update to 0.3.1

• add .desktop file
• pet portclippy
• reformat with portfmt
• drop WWW::PipeViewer::Authentication: unused and unsupported
• drop WWW::PipeViewer::PlaylistItems::favorite_video: unused and unsupported

ChangeLog: https://github.com/trizen/pipe-viewer/blob/0.3.1/Changes
PR: 266208