Remove com.microsoft.mrtk.windowsspeech's strong dependency on com.microsoft.mrtk.tts.windows

[AMollis]

This issue has been migrated a new MRTK repository, and the status of this issue will now be tracked at the following location:

• Remove com.microsoft.mrtk.windowsspeech's strong dependency on com.microsoft.mrtk.tts.windows MixedRealityToolkit/MixedRealityToolkit-Unity#170

---

Describe the problem

The WindowsTextToSpeechSubsystem is inside the com.microsoft.mrtk.windowsspeech package, and WindowsTextToSpeechSubsystem requires com.microsoft.mrtk.tts.windows. Given this strong dependency, and app is required to include com.microsoft.mrtk.tts.windows even if it doesn't require text-to-speech (TTS).

Describe the solution you'd like

Either update com.microsoft.mrtk.windowsspeech so that it disables TTS code paths if the com.microsoft.mrtk.tts.windows package is not included. Or move WindowsTextToSpeechSubsystem into a different package.

Describe alternatives you've considered

1. Leave everything as is, and always require com.microsoft.mrtk.tts.windows.
2. Move com.microsoft.mrtk.tts.windows into com.microsoft.mrtk.windowsspeech

Additional context

It's unclear as to why WindowsTextToSpeechSubsystem wasn't in com.microsoft.mrtk.tts.windows in the first place.