Support for modern CASM format

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Problem statement:

I'm trying to deploy contract built with scarb >= 2.7.0 to sepolia network using recipe from here (kindly provided by @thiagodeev). But all I got was error from the node, stating:

{
     "jsonrpc": "2.0",
     "id": 3,
     "error": {
        "code": 60,
        "message": "The compiled class hash did not match the one supplied in the transaction"
    }
}

As I need this functionality in golang I started digging and realised that library has fallen behind agains the recent casm format, especially it lacks accounting of bytecode_segment_lengths field. That results in incorrect class hash.

[baitcode]

Additionally, I forgot to mention that ABI field in casm is not string anymore, and also required workarond.

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@thiagodeev @Olexandr88

I'd be grateful if you could help me to submit those changes!

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Yay