Tracking Issue: Validate coinbase transactions, including the dev fund

[teor2345]

Motivation

We need to validate coinbase transactions.

Since we're checkpointing on Canopy, we can ignore Founders Reward validation.

Tasks

Overall ticket: #338

Canopy onwards:

• coinbase amount and halving intervals (Block Subsidy and Founders Reward Amounts #1051)
• miner subsidy
• transaction fees to miners

Testing:

• Create test blocks that send multiple outputs to a funding stream address
  • correct address, different amount
  • different address, correct amounts
  • correct address, correct amount, multiple times
  • correct address, multiple transfers that sum to correct amount (should fail)
  • these tests should pass if there is at least one transfer to the correct address with the correct amount, and fail otherwise

Canopy until second halving:

• dev fund: funding stream amounts, addresses, and height ranges
  • Mainnet
  • Testnet
• test blocks between Canopy and first halving on testnet: they must obey the dev fund rules
• test blocks after first halving on mainnet and testnet

[teor2345]

Updated to add transaction fees, and correct the network upgrades for each check.