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

hal/src/main/native/sim/MockHooks.cpp

@@ -8,6 +8,7 @@
 #include <cstdio>
 #include <thread>
 
+#include <fmt/format.h>
 #include <wpi/timestamp.h>
 
 #include "MockHooksInternal.h"
@@ -83,7 +84,7 @@ void HALSIM_WaitForProgramStart(void) {
   int count = 0;
   while (!programStarted) {
     count++;
-    std::printf("Waiting for program start signal: %d\n", count);
+    fmt::print("Waiting for program start signal: {}\n", count);
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
   }
 }