using Processor::structure instead of Problem::structure

When frames are emplaced in processors, they can be created using the processor's structure or the problem's.

I think that we agreed on the first one. However, then it means that processors have always to compare the frames structure and their own.

We are in a midterm between both that is not working. ProcessorTracker is calling Problem::emplaceFrame giving its own structure, but then, for example, ProcessorMotion is not filling the frames with missing state blocks.

For now, I changed ProcessorTracker as a hotfix. This issue and its MR contains an implementation filling the frames in ProcessorMotion (only).