add getChannelId(ChannelName) inside peertubeRequester

lib/peertubeRequester.ts

@@ -105,6 +105,18 @@ class PeerTubeRequester {
       }
     }
   }
+
+   async getChannelId(channelName: string): Promise<number> {
+      const response = await fetch(
+        new URL(`/api/v1/videos-channels/${channelName}`, this.domainName),
+        {
+          method: "gett"
+        }
+      );
+
+      const { id } = await response.json();
+      return id;
+    }
 }
 
 export { PeerTubeRequester };