Add blaze powder as rare trail ruin loot

Currently the following two major features are impossible to reach on a random world when playing in peaceful mode:

• The End
• Brewing

This is, because there is no way to obtain blaze powder in peaceful mode, since blazes don't spawn as they are hostile mobs.

As a way around this I would propose to add blaze powder as a rare (<2%) drop from suspicious gravel with the rare loot table type in the new trail ruins.

This should not have a negative influence on the gameplay experience disencouraging (non-peaceful) players to enter the nether, because the combined rarity of trail ruins, getting the right loot type and and then rolling blaze powder would likely make it way easier to obtain blaze rods in a nether fortress. On the other hand it introduces a new way for peaceful players to beat the game at all and to brew potions, thereby greatly expanding the peaceful gameplay.

I think this also makes sense from a lore perspective. The inhabitants of the trail ruins were obviously good at craftsmanship, as we can see from the smithing templates and sherds they left behind. Therefore it would - in my opinion - make sense that they might have entered the nether and gotten blaze powder, although not yet knowing what to do with it, so they left it behind.