fix: activities on private object not visible by owner

[ThibaudDauce]

👋 je vois que l'API ne renvoie les activités d'un objet private que pour les super-admin

udata/udata/core/activity/api.py

Lines 112 to 117 in 5313356

	if hasattr(item.related_to, "private") and (
	current_user.is_anonymous or not current_user.sysadmin
	):
	if item.related_to.private:
	continue
	safe_items.append(item)

Est-ce que ce serait envisageable d'introduire un check de type visible_by_user plutôt ?

⚠️ need fixing if merged before or after #3566

[maudetes]

Thank you for taking a go a it!

I think the existing activity logic filtering quite terrible 😢, but it should probably be investigated in a different iteration

[maudetes]

I think it may be confusing with the is_visible computed properties that exist on multiple objects and that also takes other properties into account (deleted, archived, etc.), not behaving the same as this.

[ThibaudDauce]

What do you think of ea1cf23?