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/include/armnn/Types.hpp b/include/armnn/Types.hpp
index 7f2e192..4f39ebe 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -50,7 +50,8 @@
 {
     NCHW = 1,
     NHWC = 2,
-    NDHWC = 3
+    NDHWC = 3,
+    NCDHW = 4
 };
 
 /// Define the behaviour of the internal profiler when outputting network details