load NodeOracle from image tag

load_node_oracle.ts

const oracle = new NodeOracle({
  chain: "solana",
  // use the latest testnet (devnet) version of the oracle
  imageTag: "testnet-2.0.7",
  // disables production capabilities like monitoring and alerts
  network: "localnet",
  rpcUrl: provider.connection.rpcEndpoint,
  oracleKey: switchboard.oracle.publicKey.toBase58(),
  // path to the payer keypair so the oracle can pay for txns
  secretPath: switchboard.walletPath || "~/.config/solana/id.json",
  // set to true to suppress oracle logs in the console
  silent: false,
  // optional env variables to speed up the workflow
  envVariables: {
    VERBOSE: "1",
    DEBUG: "1",
    DISABLE_NONCE_QUEUE: "1",
    DISABLE_METRICS: "1",
  },
});