Rename JFX threads to use consistent naming conventions.

We have some threads that use spaces in their names, ie. "JavaFX Application Thread" and "Prism Font Disposer"

Others do not use spaces, i.e. "JavaFX-Launcher" and "QuantumRenderer-0"

Should we drop the word "Thread" from "JavaFX Application Thread" name? None of the other thread names use that word in their descriptions.