[Frontend] Enable decord to load video from base64

[DarkLight1337]

Currently, only base64 URLs based on image frames are supported because pillow is always being used to decode the individual frames. This PR enables the use of decord to load the video (just like the case for HTTP URLs) so that other types of videos can also be passed in online inference.

FIX #10994 (comment)

[github-actions]

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