Drift 2.25.0

Core drift package:

• Report SqliteExceptions occurring on workers as SqliteException instances. Previously, they were sent as strings only.
• Fix LazyDatabase being closed without ever being used potentially leaking resources.

In the generator:

• Fix incorrect code when applying non-nullable type converters with a nullable JSON type to nullable column.
• Fix missing outputs for drift files only consisting of imports in modular generation mode.
• Allow generating manager references across different files in modular generation mode.
• Fix class names with dollar signs not being escaped in drift-generated toString().
• Make-migrations command: Use flutter_test if the core test package is unavailable and warn when database class needs changes for test.