Add behavior IVersionable to Portal

[wesleybl]

This is part of: plone/volto#5284

In order for the working copy of plone.app.iterate to work in the Portal, it needs to be versionable and have the IVersionable behavior. See:

https://github.com/plone/plone.app.iterate/blob/1908aa1f4e9c95c37143fae88655469b72ea451a/plone/app/iterate/browser/control.py#L50-L52

[mister-roboto]

@wesleybl thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[wesleybl]

@jenkins-plone-org please run jobs

[mauritsvanrees]

What I don't like about this, is that we would then have two behaviors: plone.versioning and plone.versioning.portal. This is visible in the Isn't there some interface that is shared between the Plone Site root and normal Dexterity content?

[davisagli]

@wesleybl Like Maurits, I don't understand why a new behavior is needed. Can't we just enable the existing behavior for the Plone Site content type? The portal object should have the IDexterityContent interface starting in Plone 6.0.

[wesleybl]

The portal object should have the IDexterityContent interface starting in Plone 6.0

@mauritsvanrees @davisagli this is true when you create a Classic Plone Site. But when you create a modern Plone Site, something happens and it stops working. This may require further investigation.