refactor(migrations): migrate package files (#16393)

* create file

* use class-based migration for packageFiles

* add tests

* fix errors

* fix merge errors

* Update lib/config/migrations/custom/package-files-migration.ts

Co-authored-by: Jamie Magee <jamie.magee@gmail.com>

* Update lib/config/migrations/custom/package-files-migration.ts

Co-authored-by: Jamie Magee <jamie.magee@gmail.com>

* add test

* Update index.ts

* modify test

* fix type

* refactor

* Update lib/config/migrations/custom/package-files-migration.ts

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Update lib/config/migrations/custom/package-files-migration.ts

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* readd todo

Co-authored-by: Jamie Magee <jamie.magee@gmail.com>
Co-authored-by: Michael Kriese <michael.kriese@visualon.de>