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

cscore/src/main/native/cpp/RawSinkImpl.h

@@ -9,9 +9,9 @@
 
 #include <atomic>
 #include <functional>
+#include <string_view>
 #include <thread>
 
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 
 #include "Frame.h"
@@ -23,9 +23,9 @@ class SourceImpl;
 
 class RawSinkImpl : public SinkImpl {
  public:
-  RawSinkImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  RawSinkImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
               Telemetry& telemetry);
-  RawSinkImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  RawSinkImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
               Telemetry& telemetry,
               std::function<void(uint64_t time)> processFrame);
   ~RawSinkImpl() override;