[development] fixed ambiguous 'byte' type MSVC build error (#7184)

- fully quality 'byte' type in AZStd::span
- remove unnecessary 'using namespace AZStd;' statement from AssetCatalog tests

Signed-off-by: AMZN-ScottR <24445312+AMZN-ScottR@users.noreply.github.com>

Code/Framework/AzCore/AzCore/std/containers/span.h

@@ -189,11 +189,11 @@ namespace AZStd
     // [span.objectrep], views of object representation
     template <class ElementType, size_t Extent>
     auto as_bytes(span<ElementType, Extent> s) noexcept
-        -> span<const byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>;
+        -> span<const AZStd::byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>;
 
     template <class ElementType, size_t Extent>
     auto as_writable_bytes(span<ElementType, Extent> s) noexcept
-        -> enable_if_t<!is_const_v<ElementType>, span<byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>>;
+        -> enable_if_t<!is_const_v<ElementType>, span<AZStd::byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>>;
 
 } // namespace AZStd
 

Code/Framework/AzCore/AzCore/std/containers/span.inl

@@ -197,18 +197,18 @@ namespace AZStd
 
     template <class ElementType, size_t Extent>
     inline auto as_bytes(span<ElementType, Extent> s) noexcept
-        -> span<const byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>
+        -> span<const AZStd::byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>
     {
-        return span<const byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>(
-            reinterpret_cast<const byte*>(s.data()), s.size_bytes());
+        return span<const AZStd::byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>(
+            reinterpret_cast<const AZStd::byte*>(s.data()), s.size_bytes());
     }
 
 
     template <class ElementType, size_t Extent>
     inline auto as_writable_bytes(span<ElementType, Extent> s) noexcept
-        -> enable_if_t<!is_const_v<ElementType>, span<byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>>
+        -> enable_if_t<!is_const_v<ElementType>, span<AZStd::byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>>
     {
-        return span<byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>(
-            reinterpret_cast<byte*>(s.data()), s.size_bytes());
+        return span<AZStd::byte, Extent == dynamic_extent ? dynamic_extent : sizeof(ElementType) * Extent>(
+            reinterpret_cast<AZStd::byte*>(s.data()), s.size_bytes());
     }
 } // namespace AZStd

Code/Framework/AzFramework/Tests/AssetCatalog.cpp

@@ -34,7 +34,6 @@
 
 #include "AZTestShared/Utils/Utils.h"
 
-using namespace AZStd;
 using namespace AZ::Data;
 
 namespace UnitTest