1.53.0 - Add Service Lifecycle Support

What's Changed

Add Service Lifecycle Support by @0xTim in #646

Adds support for Swift Service Lifecycle as we prepare Vapor for Vapor 5.

This allows you to add Databases to a ServiceGroup and have service lifecycle handle shutting down the connection pool when the application exits and provides a better integration with the ecosystem.

This patch was released by @0xTim

Full Changelog: 1.52.2...1.53.0