cubicweb-clinipath #3912377 Add basic entities [validation pending]

Add basic entities such as Biopsy, CellCulture, IHC data, ...

prioritynormal
typebug
done in0.1.0
load1.000
load left0.000
closed by#7784b9ac4792 [schema] First version of the cube: schema and entities, closes #3912377
patch[schema] First version of the cube: schema and entities, closes #3912377 [applied]