Listen to Input Method Events

[jperedadnr]

JavaFX built-in text input controls (TextField and TextArea) handle two type of key events: KeyEvents for regular key strokes, and InputMethodEvent for composed keys (like ``+e = è`).

RTA only handles the first type, and that works fine up until JavaFX 23-ea+6. Starting 23-ea+7, changes in macOS native code broke this, and handling the second type is now needed.

The composed mode typically has two InputMethodEvent events, the first one with a composed String and a highlight Shape, and the second, that removes both, has the final committed string.

RTA most likely can't deal with the first event (inserting the composed String will break the chain of events), but so far we will keep a valid committed string.