Improve KReportExample main window by combining designer and preview widgets
Summary:
Improve KReportExample main window by combining designer and preview widgets.
Save/restore visual state of KReportExample.
Show preview at startup in KReportExample.
Set layout of KReportView to 0, it's a QWidget so that's better default
Rename designerwindow to DesignerWidget.
Test Plan: Run the report example, make some clicks.
Reviewers: piggz
Subscribers: Kexi-Devel-list
Tags: KReport
Differential Revision: https://phabricator.kde.org/D2795