Refactor source layout

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

[no changelog]

src/main/kotlin/events/SlotRenderEvents.kt

@@ -0,0 +1,34 @@
+
+
+package moe.nea.firmament.events
+
+import net.minecraft.client.gui.DrawContext
+import net.minecraft.screen.slot.Slot
+
+interface SlotRenderEvents {
+    val context: DrawContext
+    val slot: Slot
+    val mouseX: Int
+    val mouseY: Int
+    val delta: Float
+
+    data class Before(
+        override val context: DrawContext, override val slot: Slot,
+        override val mouseX: Int,
+        override val mouseY: Int,
+        override val delta: Float
+    ) : FirmamentEvent(),
+        SlotRenderEvents {
+        companion object : FirmamentEventBus<Before>()
+    }
+
+    data class After(
+        override val context: DrawContext, override val slot: Slot,
+        override val mouseX: Int,
+        override val mouseY: Int,
+        override val delta: Float
+    ) : FirmamentEvent(),
+        SlotRenderEvents {
+        companion object : FirmamentEventBus<After>()
+    }
+}