Remove GetGraph and include of Graph.hpp header from public header

Remove deprecated GetGraph() from OptimizationViews. This method has
been deprecated for a long time and no backends still need it. Remove
include of Graph.hpp from the public headers.

Add includes elsewhere to deal with the header fallout.

Signed-off-by: Matthew Bentham <matthew.bentham@arm.com>
Change-Id: I8dae275a8a446d9d0e19be62684e9b3cd2fa493d
diff --git a/src/backends/backendsCommon/test/TestDynamicBackend.cpp b/src/backends/backendsCommon/test/TestDynamicBackend.cpp
index 5018b44..b7c9b4f 100644
--- a/src/backends/backendsCommon/test/TestDynamicBackend.cpp
+++ b/src/backends/backendsCommon/test/TestDynamicBackend.cpp
@@ -6,7 +6,7 @@
 #include "TestDynamicBackend.hpp"
 
 #include <armnn/backends/IBackendInternal.hpp>
-
+#include <armnn/backends/WorkloadFactory.hpp>
 #include <armnn/utility/IgnoreUnused.hpp>
 
 constexpr const char* TestDynamicBackendId()