Add ConstTensorsAsInput support for Conv3d

 * Constant weights and biases are now stored as Constant layers.
 * Updated Serializer, Deserializer and unit tests to reflect this.
 * Updated TfLiteParser.
 * Updated Ref backend to handle constant weights and
   bias as inputs rather than reading from member variables.
 * Added Conv3d EndToEnd test.
 * Added NCDHW DataLayout and unit tests.

Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: I10cdd354ca5f1c748730f92ffdb36bf810f83c8e
diff --git a/src/backends/backendsCommon/WorkloadData.hpp b/src/backends/backendsCommon/WorkloadData.hpp
index 29d39d1..4e56aaf 100644
--- a/src/backends/backendsCommon/WorkloadData.hpp
+++ b/src/backends/backendsCommon/WorkloadData.hpp
@@ -208,18 +208,9 @@
     void Validate(const WorkloadInfo& workloadInfo) const;
 };
 
-// Convolution 2D layer workload data.
+// Convolution 3D layer workload data.
 struct Convolution3dQueueDescriptor : QueueDescriptorWithParameters<Convolution3dDescriptor>
 {
-    Convolution3dQueueDescriptor()
-        : m_Weight(nullptr)
-        , m_Bias(nullptr)
-    {
-    }
-
-    const ConstTensorHandle* m_Weight;
-    const ConstTensorHandle* m_Bias;
-
     void Validate(const WorkloadInfo& workloadInfo) const;
 };