fix: Instagram audio rendering issues (#9957)

We are using `audio` component for rendering audio files in dashboard.

```
<audio v-else-if="isAudio" controls>
   <source :src="`${dataUrl}?t=${Date.now()}`" />
</audio>
```
We have added the timestamp for every audio URL for cache busting. For
Instagram, we are getting a signature URL. When we add any value and
access the URL, it results in an "Invalid signature. If I remove the
timestamp, the audio is rendering properly. This PR will change the
logic to construct the URL properly instead of direct string
manipulation.

app/javascript/dashboard/helper/specs/URLHelper.spec.js

@@ -5,6 +5,7 @@ import {
   conversationListPageURL,
   getArticleSearchURL,
   hasValidAvatarUrl,
+  timeStampAppendedURL,
 } from '../URLHelper';
 
 describe('#URL Helpers', () => {
@@ -190,4 +191,51 @@ describe('#URL Helpers', () => {
       expect(hasValidAvatarUrl()).toBe(false);
     });
   });
+
+  describe('timeStampAppendedURL', () => {
+    const FIXED_TIMESTAMP = 1234567890000;
+
+    beforeEach(() => {
+      vi.spyOn(Date, 'now').mockImplementation(() => FIXED_TIMESTAMP);
+    });
+
+    afterEach(() => {
+      vi.restoreAllMocks();
+    });
+
+    it('should append timestamp to a URL without query parameters', () => {
+      const input = 'https://example.com/audio.mp3';
+      const expected = `https://example.com/audio.mp3?t=${FIXED_TIMESTAMP}`;
+      expect(timeStampAppendedURL(input)).toBe(expected);
+    });
+
+    it('should append timestamp to a URL with existing query parameters', () => {
+      const input = 'https://example.com/audio.mp3?volume=50';
+      const expected = `https://example.com/audio.mp3?volume=50&t=${FIXED_TIMESTAMP}`;
+      expect(timeStampAppendedURL(input)).toBe(expected);
+    });
+
+    it('should not append timestamp if it already exists', () => {
+      const input = 'https://example.com/audio.mp3?t=9876543210';
+      expect(timeStampAppendedURL(input)).toBe(input);
+    });
+
+    it('should handle URLs with hash fragments', () => {
+      const input = 'https://example.com/audio.mp3#section1';
+      const expected = `https://example.com/audio.mp3?t=${FIXED_TIMESTAMP}#section1`;
+      expect(timeStampAppendedURL(input)).toBe(expected);
+    });
+
+    it('should handle complex URLs', () => {
+      const input =
+        'https://example.com/path/to/audio.mp3?key1=value1&key2=value2#fragment';
+      const expected = `https://example.com/path/to/audio.mp3?key1=value1&key2=value2&t=${FIXED_TIMESTAMP}#fragment`;
+      expect(timeStampAppendedURL(input)).toBe(expected);
+    });
+
+    it('should throw an error for invalid URLs', () => {
+      const input = 'not a valid url';
+      expect(() => timeStampAppendedURL(input)).toThrow();
+    });
+  });
 });