Prefer Microsoft Zira for TTS

[Vivelin]

Microsoft Zira is the "iconic" Tracker voice but Dubz, being British, got the British English TTS instead.

We only request a female voice when we initialize Tracker, but there is an overload that accepts a CultureInfo object:

var tts = new SpeechSynthesizer();
tts.SelectVoiceByHints(VoiceGender.Female, VoiceAge.NotSet, 0, new System.Globalization.CultureInfo("en-GB"));
tts.Speak("Hey tracker, track missiles"); // Microsoft Hazel (if installed, even if Zira is default)

There's also GetInstalledVoices and a SelectVoice method that accepts a name ("Microsoft Zira Desktop") so we could potentially make this configurable, too.