Don't show file chooser when using "open-project" from command bar
Currently running the "open-project" command from the command bar shows the "Open a Project" window with the "Select Project Folder" file chooser already open in front of it.
This is not consistent with the behaviour of the "Open a Project..." from the application menu.
I'd suggest that the "open-project" command should do the same as the menu item, and show the "Open a Project" window without the chooser open.
The current command behaviour is possibly a vestige from before the fix for #766 (closed).