IVGCVSW-3423 Add TfLite parser support for Stack (Pack) layer

* Added ParsePack method
* New unit test Pack.cpp
* Updated TensorFlowLiteSupport.md with new supported operator

Signed-off-by: Matthew Jackson <matthew.jackson@arm.com>
Change-Id: I2310b33ee26959b036bb4452a25c90cc1d4cbf20
diff --git a/CMakeLists.txt b/CMakeLists.txt
index dbb212f..9bc4201 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -570,6 +570,7 @@
              src/armnnTfLiteParser/test/Mean.cpp
              src/armnnTfLiteParser/test/Minimum.cpp
              src/armnnTfLiteParser/test/Multiplication.cpp
+             src/armnnTfLiteParser/test/Pack.cpp
              src/armnnTfLiteParser/test/Pad.cpp
              src/armnnTfLiteParser/test/Reshape.cpp
              src/armnnTfLiteParser/test/ResizeBilinear.cpp