Dictation: go back to the app automatically once the mic is ready

When you hold 🎙 and the mic isn't armed yet, iOS has to open the EFKey app to switch it on. Until now you then had to get back on your own, with the back arrow in the top corner or the return button in EFKey.

Starting with build 451, EFKey takes you back by itself:

1. Hold 🎙 in any app. EFKey opens and arms the mic.
2. "Taking you back to <app>" shows for half a second, with a Cancel button.
3. You land back in the app you were typing in, ready to dictate.

It only goes back when the keyboard knew for sure which app you were typing in at that moment. If it can't tell, EFKey stays open and you go back the old way. It never guesses from an app you used earlier, so it can't drop you somewhere else.

It's on by default. You can turn it off in Settings › Dictation › Return to the app.

Worth testing: Safari, WhatsApp, Discord and Telegram, both in an empty field and after typing a few words; the first dictation after a fresh install or a phone restart; switching to another app right before holding 🎙.