Added Interaction handler abstraction

lib/src/main/java/net/tomatentum/marinara/handler/InteractionHandler.java

@@ -0,0 +1,4 @@
+package net.tomatentum.marinara.handler;
+
+public interface InteractionHandler {
+}

lib/src/main/java/net/tomatentum/marinara/interaction/InteractionType.java

@@ -0,0 +1,9 @@
+package net.tomatentum.marinara.interaction;
+
+public enum InteractionType {
+    COMMAND,
+    AUTOCOMPLETE,
+    BUTTON,
+    SELECT_MENU,
+    MODAL
+}