feat: Implement getData query and send a message action for slack

packages/backend/src/apps/slack/data/list-channels.ts

@@ -0,0 +1,21 @@
+import type { IJSONObject } from '@automatisch/types';
+import { WebClient } from '@slack/web-api';
+
+export default class ListChannels {
+  client: WebClient;
+
+  constructor(connectionData: IJSONObject) {
+    this.client = new WebClient(connectionData.accessToken as string);
+  }
+
+  async run() {
+    const { channels } = await this.client.conversations.list();
+
+    return channels.map((channel) => {
+      return {
+        value: channel.id,
+        name: channel.name,
+      };
+    });
+  }
+}