Fix compilation error when building with CMake and Clang

RefBase::Detatch() method in RefBase.h calls std::move,
but no appropriate header was included. Error example was:
RefBase.h:137:22: error: no member named 'move' in namespace 'std'

Change-Id: I60f84bffba06ba5fd3fea7fb9c4908cfe3989472
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/56281
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

src/common/RefBase.h

@@ -19,6 +19,7 @@
 #include "common/Compiler.h"
 
 #include <type_traits>
+#include <utility>
 
 // A common class for various smart-pointers acting on referenceable/releasable pointer-like
 // objects. Logic for each specialization can be customized using a Traits type that looks