Refactor source layout

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

[no changelog]

src/main/kotlin/events/AttackBlockEvent.kt

@@ -0,0 +1,18 @@
+
+package moe.nea.firmament.events
+
+import net.minecraft.entity.player.PlayerEntity
+import net.minecraft.util.Hand
+import net.minecraft.util.math.BlockPos
+import net.minecraft.util.math.Direction
+import net.minecraft.world.World
+
+data class AttackBlockEvent(
+    val player: PlayerEntity,
+    val world: World,
+    val hand: Hand,
+    val blockPos: BlockPos,
+    val direction: Direction
+) : FirmamentEvent.Cancellable() {
+    companion object : FirmamentEventBus<AttackBlockEvent>()
+}