Replace std::snprintf() with wpi::format_to_n_c_str() (#5645)

fmtlib uses consteval format string processing, which makes it more
efficient than std::snprintf().

snprintf()s in libuv, mpack, processstarter, and wpigui were left alone.
processstarter uses stdlib only, and wpigui only depends on imgui.

fmt::format_to_n() is analogous to std::format_to_n()
(https://en.cppreference.com/w/cpp/utility/format/format_to_n)

wpi::format_to_n_c_str() is a wrapper which adds the trailing NUL.

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

@@ -4,6 +4,8 @@
 
 #include "glass/hardware/AnalogGyro.h"
 
+#include <wpi/StringExtras.h>
+
 #include "glass/DataSource.h"
 #include "glass/other/DeviceTree.h"
 
@@ -11,7 +13,8 @@ using namespace glass;
 
 void glass::DisplayAnalogGyroDevice(AnalogGyroModel* model, int index) {
   char name[32];
-  std::snprintf(name, sizeof(name), "AnalogGyro[%d]", index);
+  wpi::format_to_n_c_str(name, sizeof(name), "AnalogGyro[{}]", index);
+
   if (BeginDevice(name)) {
     // angle
     if (auto angleData = model->GetAngleData()) {