Use wpi::span instead of wpi::ArrayRef across all libraries (#3414)

- Remove ArrayRef.h
- Add SpanExtras.h for a couple of convenience functions

glass/src/libnt/native/cpp/NTFMS.cpp

@@ -7,6 +7,7 @@
 #include <stdint.h>
 
 #include <fmt/format.h>
+#include <wpi/SmallVector.h>
 #include <wpi/timestamp.h>
 
 using namespace glass;