Migrate Suppliers to DX

[Bugerman58]

Description of the issue/feature this PR addresses

This PR migrates the AT Supplier and Suppliers to Dexterity types for Python 3 compatibility.

Current behavior before PR

Supplier and Suppliers are content types based on the Archetypes framework

Desired behavior after PR is merged

Supplier and Suppliers are content types based on the Dexterity framework

--
I confirm I have tested this PR thoroughly and coded it according to PEP8
and Plone's Python styleguide standards.

[Bugerman58]

Hi @ramonski
This PR ready for review. Pls, check it )

[xispa]

Awesome @Bugerman58 ! I've left some comments, keep it going!

[xispa]

Just noticed that addresses were partially migrated, see comments. We are almost there!

[xispa]

Excellent, thanks @Bugerman58 !

[ramonski]

Running the same upgrade step once again raises a traceback:

Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 176, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 385, in publish_module
  Module ZPublisher.WSGIPublisher, line 288, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 63, in call_object
  Module Products.GenericSetup.tool, line 1135, in manage_doUpgrades
  Module Products.GenericSetup.upgrade, line 185, in doStep
  Module senaite.core.upgrade, line 39, in wrap_func_args
  Module senaite.core.upgrade.v02_06_000, line 1758, in migrate_suppliers_to_dx
  Module senaite.core.upgrade.utils, line 363, in uncatalog_object
AttributeError: 'NoneType' object has no attribute 'unindexObject'

@Bugerman58: Would you mind to create a new PR to handle this gracefully?

[Bugerman58]

Running the same upgrade step once again raises a traceback:

Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 176, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 385, in publish_module
  Module ZPublisher.WSGIPublisher, line 288, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 63, in call_object
  Module Products.GenericSetup.tool, line 1135, in manage_doUpgrades
  Module Products.GenericSetup.upgrade, line 185, in doStep
  Module senaite.core.upgrade, line 39, in wrap_func_args
  Module senaite.core.upgrade.v02_06_000, line 1758, in migrate_suppliers_to_dx
  Module senaite.core.upgrade.utils, line 363, in uncatalog_object
AttributeError: 'NoneType' object has no attribute 'unindexObject'

@Bugerman58: Would you mind to create a new PR to handle this gracefully?

Hi @ramonski

oh, sure. I'll fix this error soon