[Feature Request] Hide video duration

[eemil]

Knowing how much time is left can sometimes spoil a video.

It would be nice if I could hide duration from video thumbnails and within YouTube's player.

For this particular feature, a channel-based blacklist would be useful in addition to just "on" and "off".

[VampireChicken12]

@eemil Good idea. The code is currently undergoing a major change to the translation files, but once that's done, I'll look into it.