Function calculate_block_reward

pub fn calculate_block_reward(
    block_weight: usize,
    median_bw: usize,
    already_generated_coins: u64,
    hf: HardFork,
) -> u64

Calculates the miner reward for this block.

ref: https://monero-book.cuprate.org/consensus_rules/blocks/reward.html#calculating-block-reward