• Core refactoring to support multiple parents for actions - All methods changed in the actions - Icons for all actions

Summary:
Fixes T8138

Ref T1625

Test Plan:

• You need to implement a 'parents' method instead of 'parent' for each action
• That method returns a tuple with all parent widgets
• You can hide the icon on the menu using self.setIconVisibleInMenu(False)

Reviewers: woltherav, rempt

Subscribers: eliakinalmeida

Maniphest Tasks: T8138, T1625

Differential Revision: https://phabricator.kde.org/D11247