chan: print out actual anim info when showing AnimBundleNode in ls()

This allows one to more easily discover the animations present in a scene graph, such as when using bam-info -ls to inspect a .bam file.

panda/src/chan/animBundleNode.cxx

@@ -68,6 +68,19 @@ find_anim_bundle(PandaNode *root) {
   return nullptr;
 }
 
+/**
+ *
+ */
+void AnimBundleNode::
+output(std::ostream &out) const {
+  PandaNode::output(out);
+  if (_bundle != nullptr) {
+    out << " (";
+    _bundle->output(out);
+    out << ")";
+  }
+}
+
 /**
  * Tells the BamReader how to create objects of type AnimBundleNode.
  */

panda/src/chan/animBundleNode.h

@@ -49,6 +49,8 @@ private:
   PT(AnimBundle) _bundle;
 
 public:
+  virtual void output(std::ostream &out) const;
+
   static void register_with_read_factory();
   virtual void write_datagram(BamWriter* manager, Datagram &me);
   virtual int complete_pointers(TypedWritable **p_list,