ICU-22298 Include <utility> in measunit.h

measunit.h uses std::pair, std::make_pair, and std::move, all of which
are declared in the <utility> header. This still compiles because many
implementations of the C++ standard library have <utility> as a
transitive dependency of other C++ standard library headers; however,
these transitive includes are not guaranteed to exist and will not exist
in some contexts (e.g. building against LLVM's libc++ with -fmodules).

icu4c/source/i18n/unicode/measunit.h

@@ -19,6 +19,7 @@
 
 #if !UCONFIG_NO_FORMATTING
 
+#include <utility>
 #include "unicode/unistr.h"
 #include "unicode/localpointer.h"