Resolve GPU details for AWS and GCP instance types

[tcibinan]

Resolves issue #3337 for AWS and GCP.

The pull request adds an optional section gpuDevice to instance type structure which has optional fields name, manufacturer and cores.

{
    "gpu": 0
}

{
    "gpu": 2
}

{
    "gpu": 2,
    "gpuDevice": {
        "name": "A10G",
        "manufacturer": "NVIDIA",
        "cores": 9216
    }
}

{
    "gpu": 2,
    "gpuDevice": {
        "name": "A10G",
        "manufacturer": "NVIDIA"
    }
}

{
    "gpu": 2,
    "gpuDevice": {
        "name": "A10G"
    }
}