Empty workflow message is incomprehensible to the user.

[morgan55555]

Current message is "Please drag'n drop a SDFX app, an image or a Comfy Workflow."
But amateur users got stuck, they don't understand, what is an app or an workflow.
Also they trying to drag'n'drop app icons from the left menu, and this is doesn't work too.
It's better to load an sdfx app as default, or add to this message "Please, select app from left menu, or ..."

[dmx974]

Fixed