[InformationPanel] Use the new inline configuration mode

Summary:
The current external configuration dialog has some issues:

- its layout is suboptimal, as its initial size is typically to small
- it is quite disassociated with the actual widget it configures, properties
  have a different order, and the property names can be quite abstract
  without the corresponding value.

Doing the visibility selection inline typically avoids the sizing problem,
as the containing application (dolphin) is often vertically maximized.
The selection becomes more obvious, as the item order is kept,
and the values are shown.

Depends on D20524

CCBUG: 389571

Reviewers: #dolphin, #baloo, #frameworks, ngraham, astippich, #vdg, elvisangelaccio

Reviewed By: #dolphin, elvisangelaccio

Subscribers: elvisangelaccio, meven, kfm-devel

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D20525