Place the output with the miner's address first in the coinbase tx

[upbqdn]

Motivation

When Zebra creates the coinbase tx, it places the output containing the miner's address last: https://testnet.zcashblockexplorer.com/transactions/ba0440859c79440692f49f6ac0630b692a01da4ed272f097ea2ea417ee41edd6, while zcashd does the opposite: https://testnet.zcashblockexplorer.com/transactions/63f30ccb9803e24c41cee97962d5dc029fa883a6ea4b7346a7ecea36285b7437. This behavior has at least two unwanted consequences:

1. Block chain explorers, such as https://zcashblockexplorer.com/, seem to rely on the order when determining the miner of the block, so the explorer will display a dev fund recipient's address as the miner of the block.
2. It is trivial to distinguish if a particular block was mined by Zebra or zcashd by looking at the placement of the output with the miner's address. It's straightforward to tell which output has the miner's address by looking at the transacted value.