Return Zstandard compressed *data* as bytes.
*level* is an int specifying the compression level to use, defaulting to
COMPRESSION_LEVEL_DEFAULT ('3').
*options* is a dict object that contains advanced compression
parameters. See CompressionParameter for more on options.
*zstd_dict* is a ZstdDict object, a pre-trained Zstandard dictionary.
See the function train_dict for how to train a ZstdDict on sample data.
For incremental compression, use a ZstdCompressor instead.