LoginOverlay should have possibility to control the visibility of the password reveal button

[OlliTietavainenVaadin]

Currently, the PasswordField has the possiblity to control whether the "reveal" button is visible or not. The LoginOverlay doesn't; this might end up in a situation where the password manager provides a "reveal" button (as can be seen on Chromium Edge without any extensions) and the password field of LoginOverlay brings its own:

[TatuLund]

The following JavaScript call can be used as workaround for LoginOverlay

overlay.getElement().executeJs("$0.$.vaadinLoginForm.$.vaadinLoginPassword.revealButtonHidden=true;", overlay.getElement());

and respectively for LoginForm

form.getElement().executeJs("$0.$.vaadinLoginPassword.revealButtonHidden=true;", form.getElement());

[web-padawan]

The root cause of two buttons is #799 which needs to be fixed.