zstd array v2

[onursatici]

The current ZstdArray interleaves string lengths with content bytes [u32 len][bytes]... and compresses them as a single blob. This forces a sequential parse of the decompressed data to reconstruct BinaryView entries, and because this is tricky to do in gpu's, we make a round trip to the host for varbinview conversion.

I think it would be useful to have another zstd array encoding, that acts on a varbinview array, compresses the views and the data buffers. Once uncompressed, this would be immediately usable for the upstream encodings as a varbinview array

[onursatici]

filed #6362