Refactor source layout

Introduce compat source sets and move all kotlin sources to the main directory

[no changelog]

src/main/kotlin/events/UseBlockEvent.kt

@@ -0,0 +1,11 @@
+
+package moe.nea.firmament.events
+
+import net.minecraft.entity.player.PlayerEntity
+import net.minecraft.util.Hand
+import net.minecraft.util.hit.BlockHitResult
+import net.minecraft.world.World
+
+data class UseBlockEvent(val player: PlayerEntity, val world: World, val hand: Hand, val hitResult: BlockHitResult) : FirmamentEvent.Cancellable() {
+    companion object : FirmamentEventBus<UseBlockEvent>()
+}