Split EventHandler into multiple different handlers

Better organization allows for finding things easier

src/main/java/WayofTime/bloodmagic/annot/Handler.java

@@ -0,0 +1,8 @@
+package WayofTime.bloodmagic.annot;
+
+/**
+ * Classes annotated with this will automatically be registered to the
+ * {@link net.minecraftforge.common.MinecraftForge#EVENT_BUS}.
+ */
+public @interface Handler {
+}