nerf 'major_positive' gossip

Currently, the 'major_positive' gossip type (exclusive to Java Edition) is too overpowered. I like the concept of getting discounts from villagers that you cured, but the discounts are very overpowered and can be exploited. The gossip never decays (unlike other gossip types), and makes most good trades take about 1 emerald to use. It should maybe be more like the equivalent of Hero of the Village 5.