ZIP 2009: reduce marginal_fee to 400 and raise weight_ratio_cap to 13

Updates draft ZIP 2009 (#1388) to propose marginal_fee = 400 zatoshis per logical action (minimum conventional fee 800 zatoshis) and weight_ratio_cap = 13, instead of 1,000 and 10. 800 zatoshis is about 0.64 cents at $800/ZEC, still about 2x the 2022 dollar cost; it only falls below the 2022 cost if ZEC drops below $375. A cap of 13 is the smallest integer above the 12.5x ratio between the old and new conventional fees, so transactions from wallets still paying the old fee are not clamped.

Radar summary of the original source