Multiple errors default entity schematic

[NanoPish]

There are different errors when adding an entity to an api using the default entity schematic, like

from app.product import Product in interface_test.py.template

or different .data in generated *_test.py files that make test crashes.

Do I miss something or should it be fixed ?

I can fix those and few others if needed.

[ehoeffner]

I entered a pull-request to see if I could get these issues addressed