Add Tensor related utilities to the new API

A couple of utility functions to get the information
about tensors are added. Those functions are placed
at an additional header file for better grouping.
Related test cases are also added.

Resolves: COMPMID-4376

Change-Id: I6bd09cbf60fddcf4fe651906982397afb0451392
Signed-off-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5405
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/cpu/CpuTensor.cpp b/src/cpu/CpuTensor.cpp
index 79dc812..6dd6d9c 100644
--- a/src/cpu/CpuTensor.cpp
+++ b/src/cpu/CpuTensor.cpp
@@ -72,7 +72,7 @@
     return bool(st) ? StatusCode::Success : StatusCode::RuntimeError;
 }
 
-arm_compute::ITensor *CpuTensor::tensor()
+arm_compute::ITensor *CpuTensor::tensor() const
 {
     return _legacy_tensor.get();
 }