preselection of output device to device used in main audio

current state

the devices used for the translation audio could differ from the devices used in main audio. #55 (closed) tries to lock the input device to the selected device from main audio / echo test

output devices are not locked

goal

also lock the output device to the selection in main audio, see https://git.fairkom.net/clients/wechange/bbb-livetranslation/-/issues/55#note_30598