Let's consider the following use case (that we typically have in Scene Builder) :
- we have a set of editable ComboBox in a VBox, with initial values set
- we want to update them, by editing the first ComboBox, then the second, etc...
- when edited, the internal model is updated with the new value
- for convenience, once edited, we directly click on the next one *without typing Enter* (or type TAB)

To implement this, when the focus is lost, we need to get the text entered. Unfortunatly, the getValue() method return the previous value.
It is impossible to get the text of the ComboBox TextField.
We would need a new getText() method that would get the text for the ComboBox TextField.

(We have implemented a workaround to get the ComboBox TextField from its skin. Unfortunatly, because of RT-19588 it does not work)