Renamed 'qs' (render quantum size) to 'sc' (samples per channel)

Following the rest of the renaming.

Author: cwoffenden

src/audio_worklet.js

@@ -36,7 +36,7 @@ function createWasmAudioWorkletProcessor(audioParams) {
       // 1.1: the typed array passed to process() should be the same size as this
       // 'render quantum size', and this exercise of passing in the value
       // shouldn't be required (to be verified).
-      this.samplesPerChannel = opts['qs'];
+      this.samplesPerChannel = opts['sc'];
     }
 
     static get parameterDescriptors() {

src/library_webaudio.js

@@ -296,7 +296,7 @@ let LibraryWebAudio = {
       processorOptions: {
         'cb': callback,
         'ud': userData,
-        'qs': emscriptenGetContextQuantumSize(contextHandle)
+        'sc': emscriptenGetContextQuantumSize(contextHandle)
       }
     } : void 0;