feat: add services page and API endpoints for service cost breakdown

- Implemented new API endpoints for fetching global services and service tenants details.
- Created a new services.html page with a sidebar for navigation and a chart for service costs.
- Updated frontend JavaScript to handle service data loading and rendering.
- Enhanced the dashboard with provider filtering options for AWS and Azure.
- Added a segmented toggle for selecting the date range for service costs.
- Improved styling for the sidebar and data tables.
- Refactored common utility functions for better reusability across pages.

frontend/static/common.js

@@ -43,6 +43,10 @@ function dayLabel(isoDate) {
   return new Intl.DateTimeFormat("fr-FR", { day: "2-digit", month: "short", timeZone: "UTC" }).format(d);
 }
 
+function rangeLabel(days) {
+  return days === 1 ? "aujourd'hui" : `${days} derniers jours`;
+}
+
 function providerLabel(provider) {
   return provider === "aws" ? "AWS" : provider === "azure" ? "Azure" : provider;
 }