Use std::string_view and fmtlib across all libraries (#3402)

- Twine, StringRef, Format, and NativeFormatting have been removed
- Logging now uses fmtlib style formatting
- Nearly all uses of wpi::outs/errs have been replaced with fmt::print() or
std::puts()/std::fputs() (for unformatted strings).
- A wpi/fmt/raw_ostream.h header has been added to enable
fmt::print() with wpi::raw_ostream

simulation/halsim_gui/src/main/native/cpp/AddressableLEDGui.cpp

@@ -9,7 +9,6 @@
 #include <hal/Ports.h>
 #include <hal/simulation/AddressableLEDData.h>
 #include <imgui.h>
-#include <wpi/StringRef.h>
 
 #include "HALSimGui.h"