Change Builder descriptors constructor

Builder descriptors are now directly initialized with fluidx descriptor.
Add model check in BuilderModel constructor
Bug fix in Builder Model structure display
Bug fix in Builder Simulation Run display
Bug fix when adding a Unit

* Added default input data when adding a new Unit to the domain
* Added Domain modules updates on initialization
Merge pull request #55 from alibres/builder-with-descriptors

Bug fixes in Builder with descriptors