Summary: Added primitive support for the mpriscontrol plugin on Windows by simulating VK_MEDIA key presses. I took a look into `ISystemMediaTransportControls`, but there doesn't seem to query it since it's per app. Leaving simulating key presses our only option for now. Completes T10000
Reviewers: kdeconnect, #kde_connect, albertvaka
Reviewed By: #kde_connect, albertvaka
Subscribers: albertvaka
Tags: #kde_connect, #windows
Maniphest Tasks: T10000
Differential Revision: https://phabricator.kde.org/D17702
