don't rely on star imports from synthDriverHandler (#12172)
* synthDriverHandler: Remove unused imports, standardize copyright header
* sayAllHandler: Remove unused import of synthDriverHandler
* settingsDialog: don't rely on star imports from synthDriverHandler
* globalCommands: don't rely onn star imports from synthDriverHandler, remove unused imports
* update changes.t2t
Co-authored-by: buddsean <sean@nvaccess.org>
