benchmarks: benchmark dask

[flying-sheep]

See #30 (comment)

We could create random dask arrays something like this:

import dask.array as da

arr = da.zeros(shape, dtype=dtype, chunks=_half_chunk_size(shape))
return arr.map_blocks(
    lambda x: self.random(x.shape, dtype=x.dtype, gen=gen), dtype=dtype
)

cc @ilan-gold