Print DNA hash in hc package output

[maackle]

• my changes to the code affect some exposed aspect of the developer experience, and I have added an item to relevant 'Added, Fixed, Changed, Removed, Deprecated, or Security' heading under the 'Unreleased' heading of the CHANGELOG, with the format - summary of change [PR#1234](https://github.com/holochain/holochain-rust/pull/1234)

[zippy]

This is great because there's an issue that folks need to remember, which is that the hash in the conductor config will eventually get checked against what's actually in source dna file, and what's in the cas at boot-up time. This helps get it for putting into the config!