Add fromspan method for NDArray and optimize NDArray loading performance

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Added the ability to load an NDArray from span< bytes >, completed loading of various missing types, and optimized the loading time using marshaling instead of BitConverter.

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Note: I added the fromspan method to the np.frombuffer.cs file. It may be preferable to create a separate np.fromspan.cs file, but I did not do that. Using span< bytes > is faster in parsing scenarios to avoid allocating byte arrays.