Better cost management with billing groups

Aiven introduces Billing Groups to streamline invoicing and cost monitoring for organizations with multiple projects. This feature allows users to combine the costs of associated projects, receive a single invoice, or set up separate yet consolidated invoices for different environments. The new Invoice API enables viewing project costs broken down into line items, which can be exported to BI tools for tracking and visualizing spending information. These enhancements make Aiven more suitable for enterprise-level workloads.