Replace deprecated Google OAuth OOB flow (#12602)

Replace deprecated Google OAuth OOB flow (#12602)

This replaces the deprecated OOB OAuth flow used in the Nest Binding and Google STT/TTS add-ons.

Instead they will now use https://www.google.com as redirect_uri.
The instructions in the README and config descriptions have been updated for this change.

See: https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html#disallowed-oob

Fixes #12455

Signed-off-by: Wouter Born <github@maindrain.net>