add pickup point selection for pickup_point delivery

[yusuphjoluwasen]

Ability of a user to select a pickpoint location for an order.

fetch pickup points from:

• GET /api/shipping/pickup-points

Query should use:

• country
• address (postcode)
• radius

Requirements:

• render pickup points in a user-friendly list
• allow user to select one pickup point
• clearly show selected point
• prevent checkout submission until a pickup point is selected for pickup-point delivery
• clear selected pickup point if shipping option changes away from pickup-point delivery

Acceptance criteria:

• pickup-point options can be loaded and selected
• selected pickup point is stored in checkout state
• validation blocks submit when required pickup point is missing

API-docs: https://cherry-backend-401854471349.europe-west2.run.app/api-docs

Figma design:

https://www.figma.com/design/E2MZsDUl54mmFzLAeqrbAb/cherry--MVP-Design---Prototype?node-id=11401-6786&t=CEGzulcqrZIFEx5R-4

https://www.figma.com/design/E2MZsDUl54mmFzLAeqrbAb/cherry--MVP-Design---Prototype?node-id=11401-6932&t=CEGzulcqrZIFEx5R-4

https://www.figma.com/design/E2MZsDUl54mmFzLAeqrbAb/cherry--MVP-Design---Prototype?node-id=11401-7180&t=CEGzulcqrZIFEx5R-4