Discontinue publishing under the hashgraph namespace #3387

[SimiHunjan]

Dual publishing continues until release v0.50.0. When we publish release v0.51.0 it should only be under hiero namespace.
cc: @rbarker-dev @andrewb1269hg

[rbarker-dev]

This means that we need to do the switchover prior to January so that the code-base is hiero-centric. I will create a new issue to put that together.

@SimiHunjan this first change will likely create some merge conflicts so i'd like to coordinate putting it in.

[rbarker-dev]

Created #1128 to handle the switchover.