Add types and stop the timer after download completed

frontend/src/Task.svelte

@@ -5,19 +5,39 @@
   export let url: string
 
   let intervalID: NodeJS.Timer
-  let task
-  let videoInfo
+
+  let task: {
+    ID: string,
+    Status: number,
+    Filename: string
+  }
+  
+  let videoInfo: {
+    ID: string,
+    Title: string,
+    Duration: number,
+    Thumbnails: any[],
+    Filename: string,
+    DownloadPath: string
+  }
 
   onMount(startDownload)
 
   async function startDownload() {
     const res = await fetch(`${endpoint}/task`, {method: 'POST', body: new URLSearchParams({'url': url})})
     videoInfo = await res.json()
-    
+
     if (res.ok) {
       intervalID = setInterval(async () => {
-	const res = await fetch(`${endpoint}/task/${videoInfo.ID}`);
-	task = await res.json();
+	const res = await fetch(`${endpoint}/task/${videoInfo.ID}`)
+	task = await res.json()
+
+	if (res.ok) {
+	  if (task.Status == 2) {
+	    clearInterval(intervalID)
+	  }
+	}
+	
       }, 2000)
     }