Replace the Sound View dialog with a wxWidgets-based one.

* Removes the one that was orignally based entirely on the DeSmuME one, while still looking most the same but cleaner.
* To accommodate this, I needed to rework how wxWidgets was initialized so the configuration dialog boxes could also work alongside this.
* Needed to add a custom wxApp to handle the above.
* This also means that the configuration dialog no longer needs the plugin's HINSTANCE passed along.
* Had to not disable wxGauge or wxToogleButton for the Sound View dialog.
* Also remove the now-unneeded enums in the XSFConfig*.cpp files.
* Sound View is still done in a thread so its event loop can run independently from the rest of the plugin.
* XSFConfig_NCSF doesn't need to be the one to start the Sound View dialog now.