Handle ScriptAtLeast deserialization for large values

[satran004]

There is a change in the type for the 'required' field in ScriptAtLeast (script_n_of_k) in the Conway era.

    //Till Babbage Format :  script_n_of_k = (3, n: uint, [ * native_script ])
    //Conway Format         :  script_n_of_k = (3, int64, [* native_script])

Sample Cbor hex :

820083031affffb5ff858202828200581c1c12f03c1ef2e935acc35ec2e6f96c650fd3bfba3e96550504d5336183031afff6b79a8182051a0005561382051a0003dd4683031a000491b58182041a0004dc05820180820180