CMake builds ManagerLinux.cpp on `!MAC && !WIN`, that is BSD and Linux.
Fix the Linux-only assumption in the shared header.

Qt's `Q_OS_UNIX` is defined on Linux, BSDs and macOS alike.

See also:
https://daniel.haxx.se/blog/2023/01/08/copyright-without-years/
https://hynek.me/til/copyright-years/

This adds functionality for viewing joined rooms and activating rooms.

I think old clang-format is just buggy in those cases, so we should
reenable those blocks, once everyone has 13 or up.

This does away with the nice abstraction layers in order to easily get the best-looking notifications for each platform.

Loren Burkholder authored 4 years ago and Nicolas Werner committed 4 years ago

Actually posting the notification is now the responsibility of a private function

* Working D-Bus desktop notifications

* Remove return type on constructor

* Fix the Windows placeholder class

* Fix wrong variable name

* Fix windows and macOS versions of notificationsmanager