item: multiple inheritance for the item class

[BadrAly]

Since the item class is used now to manage two things:

1. the item record
2. the item circulation transactions

Two base classes are created for each section above in
api.record:ItemRecord, api.circulation:ItemCirculation
The main Item class inherites from these two classes.

Co-Authored-by: Johnny Mariéthoz [email protected]
Co-Authored-by: Aly Badr[email protected]

Why are you opening this PR?

re-organising the class Item

How to test?

Must have rero_ils_ui.dev
./run_tests.sh

Code review check list

• Commit message template compliance.
• Commit message without typos.
• File names.
• Functions names.
• Functions docstrings.
• Unnecessary commited files?
• Extracted translations?

[benerken]

Run-test => OK
Installed locally and tested CKO/CKI/Renew/Request. => OK

@benerken Thanks a lot for the test.

Please verify the creation of a new item.
when you type the barcode, the console shows an error "Backend returned code 400, body was: [object Object]"

The save button is disabled => Impossible to create an item.
I use the Admin UI "included" in rero-ils (via port 5000), so not a specific version on port 4200

I was able to duplicate the problem locally, however if I connect to rero_ils_ui.dev it works nicely. I am adding rero_ils_ui.dev as dependency

[rerowep]

I'am not sure it is the right way to put classes into the __init__.pyfile ?
https://docs.python.org/3/tutorial/modules.html#packages