[PATCH v23 0/6] MR2808: SNI tray implementation

[Cherser-s (＠Cherser-s)]

Adds the tray icons implementation based on org.kde.StatusNotifierItem interface usage. Does allow restarting StatusNotifierWatcher object, but will fallback to XEMBED or internal tray, if wine gets initialized when there is no StatusNotifierWatcher object registered.

--
  v23: winesni.drv: add dbus watch instead of using plain unix fds and flush
       winesni.drv: replaced the dbus connection logic with a single connection per each SNI object
       winesni.drv: wrap functions with pthread mutex locking
       winesni.drv: implement basic balloon notification support
       explorer: add winesni.drv tray implementation support
       winesni.drv: add KDE StatusNotifierItem implementation for tray

https://gitlab.winehq.org/wine/wine/-/merge_requests/2808