Move all the modules but korge and plugins to another repo

For example korge-foundation.

Since they will be plain libraries, we should be able to use amper, or have a hugely simplified gradle script.
Compilation will be faster there and here.
It will also help to keep it as compatible as possible.

I would only have two repos, the korge one and the foundation one.

Start by inventorying the repository's modules, identifying the modules to retain with korge and plugins, and reviewing the current Gradle scripts. Compare that structure with the proposed plain-library or Amper setup. Done means the modules are moved into a separate foundation repository while the project is reduced to the two proposed repositories and remains compatible.

Written by the indexing model from the issue text.