[Windows] Default audio driver (xaudio) requires directx 9.0c

Description

Since directx 9.0c is getting older all the time, and fewer modern games require it, it's becoming increasingly less likely that users have it installed on their system. So, when they first start RetroArch, the games run too fast and without any sound, and the first thing we have to tell them to do is go mess around with their drivers, which is very "dangerous" (that is, prone to n00b errors, and those errors can be a "game over" situation that leads to a broken installation that requires manually editing the config file in a text editor, etc. etc.).

Expected behavior

The default settings should put safety and compatibility ahead of performance and should at least work on as many setups as possible.

Actual behavior

Many new users' first experience is a semi-broken one that requires immediate support to resolve.

Steps to reproduce the bug

1. Install Windows 10
2. Launch RetroArch
3. Load a game -> it runs too fast and you have no sound

Bisect Results

always

Version/Commit

You can find this information under Information/System Information

• RetroArch: v1.9.1

Environment information

• OS: Windows 10
• Compiler: mingw

@twinaphex

The issue names no source file, test, or entry point. Reproduce the default xaudio behavior on Windows 10, then trace RetroArch's Windows audio-driver defaults and identify a broadly compatible choice; done means a fresh installation has sound and normal game speed without requiring manual driver or config changes.