Modernize View Properties window

Summary:
Like D12571, but for the View Properties Window. Also did a little bit of re-organization. This allows us to use a QFormLayout as the top-level layout and simplify the code a lot, including no longer using the now-unnecessary paradigm of putting a layout inside a QWidget, and ending the use of QGridLayout to make a fake and more complicated form-style layout.

Depends on D13749

Test Plan:
Window still resizes properly when the Additional Information content is shown or hidden.

Global view properties, additional information hidden:

Global view properties, additional information shown:

Per-folder view properties, additional information hidden:

Per-folder view properties, additional information shown:

Reviewers: Dolphin, elvisangelaccio, broulik, VDG

Reviewed By: Dolphin, elvisangelaccio

Subscribers: abetts, kfm-devel

Tags: Dolphin

Differential Revision: https://phabricator.kde.org/D13768