IVGCVSW-6509 Front End + Reference Workload implementation

Subtask of story: IVGCVSW-6164 Add a Pooling3d FrontEnd and Ref Implementation

* Add front end
* Add reference workload
* Add corresponding unit tests

Change-Id: Icce4146dd0a06a1da46a2def00a82d343e171750
Signed-off-by: Tamas Nyiri <tamas.nyiri@arm.com>
diff --git a/src/backends/reference/backend.mk b/src/backends/reference/backend.mk
index 7049279..0ddb16a 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -44,6 +44,7 @@
         workloads/MirrorPad.cpp \
         workloads/Pad.cpp \
         workloads/Pooling2d.cpp \
+        workloads/Pooling3d.cpp \
         workloads/PreluImpl.cpp \
         workloads/Reduce.cpp \
         workloads/RefActivationWorkload.cpp \
@@ -84,6 +85,7 @@
         workloads/RefPadWorkload.cpp \
         workloads/RefPermuteWorkload.cpp \
         workloads/RefPooling2dWorkload.cpp \
+        workloads/RefPooling3dWorkload.cpp \
         workloads/RefPreluWorkload.cpp \
         workloads/RefQLstmWorkload.cpp \
         workloads/RefQuantizeWorkload.cpp \