[Enhancement] Bring back the water ripples background animation

[loveu5522]

snapdrop of Water ripples are moveable

[schlagmichdoch]

I have responded to this question before:

The background animation is abolished purposely. Firstly, the behavior is inconsistent as implemented into Snapdrop, as it does not start again when all peers have left. This was fixed in the beginning of PairDrop. But secondly, this animation (and all versions with a smarter logic I tried) are a heavy strain on CPU and/or GPU. See #75 and b42c8a0
In the end I decided to remove the background animation in favor of speed and efficiency. I also prefer the calmness of the GUI when the PWA is running all the time.

If you really miss this, please create a new separate issue for it. If enough users really do like the animation I will try to come up with a way without it straining the CPU/GPU (probably removing transparency changes would help).

Originally posted by @schlagmichdoch in #210 (comment)

Although this is more or less a duplicate I'll leave this to be decided. If enough people prefer some background animation I'll maybe try to come up with a way.