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

wpilibc/src/main/native/cpp/smartdashboard/Mechanism2d.cpp

@@ -19,7 +19,8 @@ Mechanism2d::Mechanism2d(double width, double height,
   SetBackgroundColor(backgroundColor);
 }
 
-MechanismRoot2d* Mechanism2d::GetRoot(wpi::StringRef name, double x, double y) {
+MechanismRoot2d* Mechanism2d::GetRoot(std::string_view name, double x,
+                                      double y) {
   auto& obj = m_roots[name];
   if (obj) {
     return obj.get();