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

glass/src/lib/native/cpp/hardware/DIO.cpp

@@ -104,7 +104,7 @@ void glass::DisplayDIO(DIOModel* model, int index, bool outputsEnabled) {
 }
 
 void glass::DisplayDIOs(DIOsModel* model, bool outputsEnabled,
-                        wpi::StringRef noneMsg) {
+                        std::string_view noneMsg) {
   bool hasAny = false;
 
   ImGui::PushItemWidth(ImGui::GetFontSize() * 8);
@@ -116,6 +116,6 @@ void glass::DisplayDIOs(DIOsModel* model, bool outputsEnabled,
   });
   ImGui::PopItemWidth();
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }