Allow indexed access of scalar array elements for pva

Author: georgweiss

core/pv-pva/src/main/java/org/phoebus/pv/pva/PVAStructureHelper.java

@@ -110,8 +110,14 @@ else if (field instanceof PVAString)
             return decodeScalar(actual);
         if (type.equals("NTEnum:1.0"))
             return Decoders.decodeEnum(actual);
-        if (type.equals("NTScalarArray:1.0"))
-            return decodeNTArray(actual);
+        if (type.equals("NTScalarArray:1.0")) {
+            if(elementIndex.isPresent()){
+                return decodeNTArray(actual, elementIndex.get());
+            }
+            else{
+                return decodeNTArray(actual);
+            }
+        }
         if (type.equals("NTNDArray:1.0"))
             return ImageDecoder.decode(actual);
         if (type.equals("NTTable:1.0"))