[FE-31] Build Invoice List component with download action and loading state

[devwums]

Problem

After completing a booking, members have no UI to view and download their invoices. The invoice list is inaccessible from the main navigation.

Proposed Solution

Create frontend/cntr/InvoiceList/InvoiceList.tsx. Props: invoices: { id: string, invoiceNumber: string, amountKobo: number, status: string, createdAt: string, bookingId: string }[], onDownload: (invoiceId: string) => void, isLoading?: boolean. Renders a paginated table. Shows skeleton rows when loading, an empty state when empty, amounts formatted as ₦, and a download icon button per row. All implementation must live inside frontend/cntr/.

Acceptance Criteria

• File at frontend/cntr/InvoiceList/InvoiceList.tsx
• Shows skeleton placeholder rows when isLoading is true
• Shows empty state message when invoices.length === 0
• Amount formatted as ₦ using (amountKobo / 100).toLocaleString('en-NG')
• Download button calls onDownload(invoice.id)
• Test in frontend/cntr/InvoiceList/InvoiceList.test.tsx