[ShapeOpt] add missing init files

[armingeiser]

📝 Description
The subfolders of the python scripts folder in the ShapeOptApp had no __init__.py files.

I don't know why it works without but its good practice to have those files in each folder.

🆕 Changelog

• Added __init__.py to all submodules in ShapeOptimizationApplication

[miguelmaso]

I don't know why it works without but its good practice to have those files in each folder.

it was introduced in #3217

[philbucher]

I don't know why it works without but its good practice to have those files in each folder.

it was introduced in #3217

actually the solution from #3217 was only an intermediate solution that was removed when we switched to the new installation mechanism (#5825).
Basically #3217 enabled us to use the python-scripts properly (i.e. from Kratos.AppName import py_script.py instead of import py_script.py) This was a prerequisite for #5825

I am not sure why it works without the __init__.py. The CoSimApp has many subfolders but so far it was always working without

@roigcarlo do you know better?

[sunethwarna]

Isn't it because of the following that we can use python imports eventhough we don't have __init__.py files?

https://docs.python.org/3/whatsnew/3.3.html#pep-420-implicit-namespace-packages

[armingeiser]

Hm, maybe it works because of the namespace package thing as @sunethwarna says.

But from what i understand we are not actually using namespace packages, but all our apps should rather be "standard" packages, thus the `init.py``files should be there.

[roigcarlo]

Exactly as @sunethwarna says. As we had support for 2.x when we make the change to use standard python modules it wouldn't have worked without. In any case I still think is a good idea to have the __init__.py file, among other reasons because not all our folders are sub-modules and this is a clean way to differentiate them.