Disable Stereo Headset Effects and stub out all known code references via define (#633)

* Disable stereoheadseteffects and stub out all known code references via define

By effect this also completely removes Headset sound options from the game config, as it serves no purpose whatsoever compared to stereo.
Because it's stubbed out everywhere rather than only the necessary locations to prevent it, this should boost audio runtime slightly for everything, not just the stuff that actively used it.

* Rename DISABLE_HEADSET_STEREO_EFFECTS to ENABLE_HEADSET_STEREO_EFFECTS

* Reorganize and reduce audio Note struct

* Add performance to define description

* Rename ENABLE_HEADSET_STEREO_EFFECTS to ENABLE_STEREO_HEADSET_EFFECTS

include/config/config_audio.h

@@ -21,6 +21,14 @@
  */
 // #define DISABLE_MARIO_PITCH_SHIFTING
 
+/** 
+ * Enables the funky sound processing that takes place with sound effects, that can sometimes cause sounds like the waterfall in castle grounds to sound more unpleasant than necessary.
+ * This is not the same thing as enabling stereo audio, but it does completely represent the sole differences between the Stereo and Headset sound options.
+ * Because of this, the Headset sound option will also not appear in the file select menu with this disabled.
+ * Leaving this disabled may also be slightly beneficial for CPU performance.
+ */
+// #define ENABLE_STEREO_HEADSET_EFFECTS
+
 /**
  * Increase audio heap size to allow for larger/more custom sequences/banks/sfx to be imported without causing issues (not supported for SH).
  * Note that this is REQUIRED in order to use the extended 0C audio bank. Do not disable this if you're planning on using it. 

include/seq_macros.inc

@@ -282,8 +282,12 @@
 .endm
 
 .macro chan_stereoheadseteffects a
+#ifdef ENABLE_STEREO_HEADSET_EFFECTS
     .byte 0xd0
     .byte \a
+#else
+    // Feel free to hijack this command for something else if it's not being used!
+#endif
 .endm
 
 .macro chan_setnoteallocationpolicy a