Break core structs down into obj and leak packages

obj/entry.go

@@ -0,0 +1,24 @@
+package obj
+
+func NewEntry(inputJSON []byte) (*Entry, error) {
+	obj, err := NewObject(inputJSON)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Entry{
+		Object: obj,
+		Index:  obj.Index(),
+	}, err
+}
+
+// Entry is a parsed heap item object
+type Entry struct {
+	Object *Object
+	Offset int64
+	Index  string
+}
+
+func (s *Entry) Address() string {
+	return s.Object.Address
+}