Runtime GIF -> WEBM re-encoding#2916

Steam supports GIFs as the workshop thumbnail (example

And to consolidate the various other GIF-related tickets…

#1722
#1850
#2299
#866
#2659

VideoPlayer supports a limited set of formats, of which GIF is not a member

it may be feasible to re-encode GIF to WEBM at runtime, but we are yet to see the performance impact of doing so

i’ll look into it