Pro video thumbnail container to use full height

Summary

Fix Pro video thumbnails when they're not set to 16:9

Closes #2250 (closed)

Steps to test

• Ensure your channel is Pro
• Upload at least 1 video, if you haven't
• Go to your channel > Pro > Settings > Theme
• Tiles Aspect Ratio > Select 1:1
• Click Save
• Preview your channel. There should be no transparent space between the video area and the its title box.

Note: Video thumbnails are not working on sandboxes, so I was only able to test with the black default background for these images.

Old behavior:

Fixed:

Estimated Regression Scope

Regressions will most likely just affect how video thumbnails look on Pro page tile lists, and any other page which use the same component/class