IVGCVSW-6856 Add GATHERNd FrontEnd and Ref Implementation

* Add front end
* Add reference workload
* Add unit tests
* Add EndToEnd test

Signed-off-by: Teresa Charlin <teresa.charlinreyes@arm.com>
Change-Id: I4cebd17b18476df86162e2dda3366c10e80bd2f8
diff --git a/src/backends/backendsCommon/WorkloadUtils.hpp b/src/backends/backendsCommon/WorkloadUtils.hpp
index 2f1c5c4..0e54873 100644
--- a/src/backends/backendsCommon/WorkloadUtils.hpp
+++ b/src/backends/backendsCommon/WorkloadUtils.hpp
@@ -251,4 +251,11 @@
                                                         const DataLayout& dataLayout,
                                                         void* permuteBuffer);
 
+/// Calculates the key index values needed for GatherNd: N, ND, K, W, C (N is always 1)
+///
+/// \param inputInfo0 - TensorInfo of the corresponding input tensor: params
+/// \param inputInfo1 - TensorInfo of the corresponding input tensor: indices
+/// \return - A map with names and values for  N, ND, K, W, C
+std::map<std::string, unsigned int> CalculateGatherNdKeyIndices(TensorInfo inputInfo0, TensorInfo inputInfo1);
+
 }  //namespace armnn