Build Flatpak for Atelier

Summary:
Add manifest to build atelier
Add patch for needed qwt module.
Requires qt3d

Reviewers: Flatpak, apol

Reviewed By: Flatpak, apol

Subscribers: laysrodrigues, Atelier, Flatpak

Tags: Flatpak, Atelier

Differential Revision: https://phabricator.kde.org/D13604