Catalog manager and study manager + small changes

- Refactored the catalog and study manager so that we have both a OMX (in mod-protocolviewer) and a generic layer (in molgenis-lifelines) implementation.
- Style updates
- Moved mod-protocolviewer classes so that we have a package per feature and a clear separation between model dependent and model independent code

Please review this pull request together with molgenis-lifelines

TODO: add more tests