IVGCVSW-2559 End to end tests for Detection PostProcess

* end to end tests for Detection PostProcess float and uint8
* add anchors to AddDetectionPostProcessLayer
* add anchors to VisitDetectionPostProcessLayer
* refactor code

Change-Id: I3c5a9a4a60b74c2246b4a27692bbf3c235163f90
Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
diff --git a/src/armnn/Network.cpp b/src/armnn/Network.cpp
index 7897a81..5c70003 100644
--- a/src/armnn/Network.cpp
+++ b/src/armnn/Network.cpp
@@ -648,9 +648,13 @@
 }
 
 IConnectableLayer* Network::AddDetectionPostProcessLayer(const armnn::DetectionPostProcessDescriptor& descriptor,
-                                                         const char* name)
+                                                         const ConstTensor& anchors, const char* name)
 {
-    return m_Graph->AddLayer<DetectionPostProcessLayer>(descriptor, name);
+    const auto layer = m_Graph->AddLayer<DetectionPostProcessLayer>(descriptor, name);
+
+    layer->m_Anchors = std::make_unique<ScopedCpuTensorHandle>(anchors);
+
+    return layer;
 }
 
 IConnectableLayer* Network::AddPermuteLayer(const PermuteDescriptor& permuteDescriptor,