Convert all raw bioassay items to derived bioassays

[Nicklas Nordborg]

The raw bioassay level is problematic since it doesn't allow us to create child items. Since we no longer use any raw bioassay specific features it would be a lot nicer to have everything at the derived bioassay level. Downstream analysis can then be added as child items instead of just adding more files and annotations to existing items.

This is a huge work that require a lot of changes to existing wizards.

We also need a way to convert existing raw bioassays to derived bioassays without losing any information. We might need some help of low-level BASE functionality here.

Data releases and the Relax server is also affected.