Editor: Allow only one instance of OpenCS
Since OpenCS can handle multiple projects at the same time, there is no benefit in running multiple instances of the application (this can even cause problems with global settings).
When the user tries to start a new instance of OpenCS, instead the start window of the existing instance should be opened.
[Feature #881] Raise OpenCS New Window After Re-execution
The OpenCS startup window of the existing exist is raised when trying to
start a new instance. This is done by the new instance connection to the
existing instance's QLocalServer. Once the connection is established the
existing instance raises the startup window.
[Feature #881] Rename QLocalServer
The server name should be more unique to the project so there isn't a