V7 compatibility workaround to prevent server response containing plain-text password (WIP)
EXPERIMENTAL OnewayPasswordField removes the plain-text value of the field from the server response to value change in the PasswordField.
*** NOTE ***
- Extends the V7 compatibility PasswordField (com.vaadin.v7.ui.PasswordField)
- Does not work with shortcuts (e.g. ENTER to log in), leading to significantly worse UX!
- This is a hacky workaround