gre: provide better debugging print option so we can use expresive form

[Tomás Migone]

await sendTransaction(publisher, contracts.GNS, 'publishNewSubgraph', [
    deploymentId,
    randomHexBytes(),
    randomHexBytes(),
  ])

I'd like to eventually move to using the more expressive:
const tx = await contracts.GNS.connect(publisher).publishNewSubgraph(deploymentId, randomHexBytes(), randomHexBytes())
And then have a wait tx helper that prints debugging. We could work on that on a different PR (in the future ™️).