Make akonadi applications non bundle for macOS

Summary:
QStandardPaths::findExecutable() is not able to find bundles so akonadi
 is unable to start. Fix that generating non bundles applications.
The processes are still visible in the macos Dock, but a follow up
 patch could hide them.
See https://stackoverflow.com/questions/620841/how-to-hide-the-dock-icon

Reviewers: dvratil, dfaure

Reviewed By: dvratil

Subscribers: vonreth, dvratil, kde-pim

Tags: #kde_pim

Differential Revision: https://phabricator.kde.org/D19982