Implement billing information edit modal

Problem/Motivation:

Customer service representatives are losing valuable time navigating through multiple pages just to update a billing address. We need to eliminate this friction and give CSRs proper tools.

Proposed Resolution:

Add an "Edit" button directly within the billing address block on order view pages. When clicked, this opens a modal dialog that allows CSRs to modify all billing information without leaving the order context.

Steps to Reproduce:

Current workflow that needs improvement:

• CSR views order page
• Must navigate to separate billing management section
• Make changes through multi-step process
• Navigate back to order to verify changes

Proposed User Experience:

• CSR views order page
• Clicks "Edit" button within billing address block
• Modal opens with all billing fields populated
• Makes changes and saves directly from modal
• Updated information appears immediately in order view

Acceptance Criteria:

• Edit button appears within billing address section on order view
• Edit button opens modal dialog when clicked
• Modal contains all necessary billing address fields with current values pre-populated
• Modal closes automatically after successful save
• Updated billing address displays immediately in order view
• Proper error handling and user feedback for failed updates
• Modal is accessible and follows Drupal UI patterns