Subject metadata, webhook filters, and new collectorsLaunch week day five feature announcements

The OpenMeter team has introduced new features including subject metadata and display names, Postgres and ClickHouse collectors, webhook usage sync filters, and a LangChain example. Subject metadata and display names allow users to assign unique identifiers and descriptive names to subjects for easier identification in the UI and reports. The addition of Postgres and ClickHouse collectors enables users to import existing usage data from their databases into OpenMeter for further processing, reporting, and billing. Webhook usage sync filters now support filtering, allowing users to trigger notifications for specific usage events. Finally, an example demonstrates how to integrate OpenMeter with LangChain, a popular open-source framework for building language model applications.