[CKEditor 5] Modifier keys close WProofreader balloon

[Mgsy]

Description

Every keypress closes WProofreader balloon, so modifier keys like Ctrl, Shift, Cmd will close the balloon.

[jshaptala]

Actually, this is the expected behavior to close our balloon (correction box) for all keypress events (including modifier keys) to avoid unexpected behavior.

In future this might be solved and handled with the plugin for CKEditor 5 using your balloon implementation.