Update Invoice/Customer views

🧩 Problem Statement

The current invoices/customer form pages do not align with modern UI/UX standards.

💡 User Story

As a platform user,

I want a modernized view with a clean, consistent, and intuitive layout,

so that I can quickly manage data without confusion or unnecessary steps.

🎯 Definition of Done (DoD)

Upgrade the following lists UI:

1. Invoice list

2. Invoice details

3. Customer edit/ create forms

4. Customer > Members’ list