refactor: rename controllers to handlers and handlers to helpers (#660)

* refactor: rename controllers to handlers and handlers to helpers

* fmt

src/handlers/commands/APPLICATION_COMMAND_UPDATE.ts

@@ -0,0 +1,16 @@
+import { eventHandlers } from "../../bot.ts";
+import { ApplicationCommandEvent, DiscordPayload } from "../../types/mod.ts";
+
+export function handleApplicationCommandUpdate(data: DiscordPayload) {
+  const {
+    application_id: applicationID,
+    guild_id: guildID,
+    ...rest
+  } = data.d as ApplicationCommandEvent;
+
+  eventHandlers.applicationCommandUpdate?.({
+    ...rest,
+    guildID,
+    applicationID,
+  });
+}