MLPro-OA: Pre-release for early adopters (4)

On our way to establishing online machine learning in MLPro, we did some last-minute refactorings...

What's Changed

MLPro-OA - Online Adaptivity

• Final changes in v2.0.0 (3) by @detlefarend in #1100

Full Changelog: v1.9.3...v1.9.4