This commit performs several key refactorings within the `core`-module to improve consistency, stability, and adhere to industry best practices.
1. **Unify `Result` Type:**
Removed the specialized `Result<T>` class from `core-utils`. The entire system will now exclusively use the more flexible and type-safe `Result<T, E>` from `core-domain`. This allows for explicit, non-exception-based error handling for business logic.
2. **Adopt Flyway for Database Migrations:**
Replaced the custom `DatabaseMigrator.kt` implementation with the industry-standard tool Flyway. The `DatabaseFactory` now triggers Flyway migrations on application startup. This provides more robust, transactional, and feature-rich schema management.
3. **Cleanup and Housekeeping:**
- Removed obsolete test files related to the old migrator.
- Ensured all components align with the new unified patterns.
BREAKING CHANGE: The `at.mocode.core.utils.error.Result` class has been removed. All modules must be updated to use the `at.mocode.core.domain.error.Result` type. The custom migrator is no longer available.
Closes #ISSUE_NUMBER_FOR_REFACTORING
