Natively support encoding and decoding ndarrays in MDS

[knighton]

Description of changes:

Store NumPy NDArray.

The dtype and shape may be either static or dynamic.

Accordingly, there are four serialized formats:

• Static dtype:
  • Static shape:
    [values: size * dtype]
  • Dynamic shape:
    [ndim | shape dtype: 1] [shape: ndim * shape dtype] [values: size * dtype]
• Dynamic dtype:
  • Static shape:
    [dtype: 1] [values: size * dtype]
  • Dynamic shape:
    [dtype: 1] [ndim | shape dtype: 1] [shape: ndim * shape dtype] [values: size * dtype]

Issue #, if available:

STR-63

Merge Checklist:

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