RPC08 - add Support for ENTRYPOINT_NOT_FOUND Error in starknet_call

[wojciechos]

In RPC spec v0.8, a new error ENTRYPOINT_NOT_FOUND was introduced. It should return error code 21 when the specified entry_point_selector in starknet_call does not exist in the contract:

starkware-libs/starknet-specs@85811f9

Sample request on sepolia:

{
    "jsonrpc": "2.0",
    "method": "starknet_call",
    "params": {
        "request": {
            "contract_address": "0x78d8ada537ab1132e600b7553c3e574336c4e0f24fb584b8b2d5faff8a37590",
            "entry_point_selector": "0x11c957afc7e84fbf8aac7ff9c79910a53a64edf9a779b18b411fbb1982fb84f", //does not exist
            "calldata": []
        },
        "block_id": "pending"
    },
    "id": 1
}

Expected Response:

    "jsonrpc": "2.0",
    "error": {
        "code": 21,
        "message": "Requested entrypoint does not exist in the contract"
    },
    "id": 1
}