[Model Update]: WeekBasedMaterialDemand

[nhaenis]

Update Reason

Contrary to previous assumptions, DCM and PURS no longer use the MaterialDemand data model together due to too many different requirements. The old WeekBasedMaterialDemand model is used again by DCM and changes have been made. Its now the same data model as MaterialDemand in #587 without the property demandRate

MS1 Criteria

• [x] The model that should be updated exists
• [x] The referenced use case exists
• [x] The potential updates are discussed with all stakeholders
• [x] A decision on versioning was made in consensus with the affected parties according to the guidelines.
• [ ] The potential update will be either
  • [ ] backward compatible or
  • [x] a (chain of) migration strategy(-ies) from all non-deprecated previous versions to the new model will be developed
• [x] A modeling steward has been assigned