Update request payload to API v0.3

[splch]

Summary

Updates job submissions to use v0.3 spec. https://docs.ionq.com/v0.3

Details and comments

    ionq_json = {
        "lang": "json",
        "body": {
            ...
        },
        ...
    }

to

    ionq_json = {
        "input": {
            "format": "ionq.circuit.v0",
            ...
        },
        ...
    }