Use the new node syntax for examples dataflow

[Hennzau]

Hi! I took a look at our examples directory, and while reading through some dataflows, I noticed that there are a lot of outdated node syntaxes:

nodes:
  - id: rust-node
    custom:
      build: cargo build -p benchmark-example-node --release
      source: ../../target/release/benchmark-example-node

I think it would be better if we avoided using deprecated syntax in our example folder, as it will be one of the first things people look at.

[haixuanTao]

Absolutely!

Thanks!