refactor(helpers): separate functions into files (#667)

* refactor(helpers): separate functions into files

* idk

* idk

src/helpers/messages/add_reaction.ts

@@ -0,0 +1,27 @@
+import { RequestManager } from "../../rest/request_manager.ts";
+import { endpoints } from "../../util/constants.ts";
+import { requireBotChannelPermissions } from "../../util/permissions.ts";
+
+/** Create a reaction for the message. Reaction takes the form of **name:id** for custom guild emoji, or Unicode characters. Requires READ_MESSAGE_HISTORY and ADD_REACTIONS */
+export async function addReaction(
+  channelID: string,
+  messageID: string,
+  reaction: string,
+) {
+  await requireBotChannelPermissions(channelID, [
+    "ADD_REACTIONS",
+    "READ_MESSAGE_HISTORY",
+  ]);
+
+  if (reaction.startsWith("<:")) {
+    reaction = reaction.substring(2, reaction.length - 1);
+  } else if (reaction.startsWith("<a:")) {
+    reaction = reaction.substring(3, reaction.length - 1);
+  }
+
+  const result = await RequestManager.put(
+    endpoints.CHANNEL_MESSAGE_REACTION_ME(channelID, messageID, reaction),
+  );
+
+  return result;
+}