Remove duplicate whatsapp button componets

[dha-aa]

Summary

• Merged the logic from whatsapp-button-simple.tsx into whatsapp-button.tsx.
• Deleted the now-unnecessary whatsapp-button-simple.tsx file.
• Updated the import in app/page.tsx to use the unified whatsapp-button.tsx:

  // Before
  import { WhatsAppButton } from "@/components/whatsapp-button-simple";
  
  // After
  import { WhatsAppButton } from "@/components/whatsapp-button";

Why

Unifying the WhatsApp button into a single component makes the code easier to maintain and avoids confusion between similar files.
Cleaning up the extra file also helps keep the project organized.