Refactor source layout

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

[no changelog]

src/compat/sodium/java/SodiumChunkReloader.kt

@@ -0,0 +1,10 @@
+import me.jellysquid.mods.sodium.client.render.SodiumWorldRenderer
+import moe.nea.firmament.mixins.accessor.sodium.AccessorSodiumWorldRenderer
+
+class SodiumChunkReloader : Runnable {
+    override fun run() {
+        (SodiumWorldRenderer.instanceNullable() as? AccessorSodiumWorldRenderer)
+            ?.renderSectionManager_firmament
+            ?.markGraphDirty()
+    }
+}