Externalize migration scripts archive dir into a submodule ko-db-archive

[stevewgr]

Description

This pull request moves the src/migration/archive directory into a new Git submodule, ko-db-archive. The submodule keeps the history of migration scripts while simplifying the main repository.

Changes

• Extracted src/migration/archive directory into the ko-db-archive repository.
• Removed the archive directory from ko-db.
• Added ko-db-archive as a submodule under src/migration/archive.

Impact

• Ensures the migration scripts archive is maintained in a separate repository for better modularity and management.
• No changes to the existing workflow apart from initializing and updating the submodule in case needed, considering it optional and documented in the ko-db-archive repo.

Instructions for Submodule Setup

• Run git submodule update --init --recursive to clone and update the submodule.

Notes

• The ko-db-archive repository is hosted at: https://github.com/ko4life-net/ko-db-archive.