Add unity web gl benchmark

Unity WebGLBenchmark. 
- All source code was added, so the benchmark is self-contained
- Some files we too big (one in particular would not even be allowed to by hosted on Github because size > 100MB). They we compressed and README was updated so make notice that and also instructions on how to uncompress.
Makes sense. I forgot that split puts in everything in the index of the result, even the separator is not found. Silly me.