Consolidate Banner Assets Service for Multi-Banner Carousel Rendering

Enhancement of the existing banner service to support multi-banner carousel functionality on the new home page. The service delivers all necessary assets (images, colors, styling) plus configurable text content (subtitle, title, CTA button text) for up to 3 banners per partner, reducing API calls, improving page load performance, and supporting SFP's multi-tenant architecture for fully customized white-label branding.