Z2SoundObject, JAUSoundAnimator OK, work on Z2SoundHandles (#1968)

* d_a_tag_evtarea mostly done, work on d_a_npc

* work on d_a_npc_ash

* work on Z2SoundHandles

* Z2SoundObject, JAUSoundAnimator OK

* Update Progress.md

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Co-authored-by: randomsalience <randomsalience@gmail.com>

include/JSystem/JSupport/JSUList.h

@@ -97,6 +97,8 @@ public:
 
     JSULink<T>* getLast() const { return (JSULink<T>*)getLastLink(); }
 
+    JSULink<T>* getNth(int index) { return (JSULink<T>*)getNthLink(index); }
+
     JSULink<T>* getEnd() const { return NULL; }
 
     u32 getNumLinks() const { return this->JSUPtrList::getNumLinks(); }