Chat search and billing improvements

This patch release adds a new chat search endpoint and fixes billing event processing.

Features

• Chat search endpoint #1425 - Added a new endpoint to list and search chats grouped by ID. (Author: @tgmendes)

Bug fixes

• Billing usage report parsing #1464 - Fixed an issue where Loops rejected billing_usage_report events due to incorrect start_time parsing. (Author: @danielkov)