Add native staking rewards for testnet

### Problem

Prior to the recent testnet reset there were staking rewards, however, there doesn't appear to be any rewards since the reset:
https://hashscan.io/testnet/nodes

### Solution

Add testnet HBAR for native staking rewards.

### Alternatives

_No response_

Start by reviewing the testnet node rewards shown at https://hashscan.io/testnet/nodes and comparing them with behavior before the reset. Trace how native staking rewards are configured and distributed; done means testnet nodes receive HBAR rewards again after the reset.

Written by the indexing model from the issue text.