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.

hal/src/main/native/cpp/jni/simulation/DriverStationDataJNI.cpp

@@ -4,8 +4,7 @@
 
 #include <jni.h>
 
-#include <cstring>
-
+#include <wpi/StringExtras.h>
 #include <wpi/jni_util.h>
 
 #include "CallbackStore.h"
@@ -539,11 +538,12 @@ Java_edu_wpi_first_hal_simulation_DriverStationDataJNI_setMatchInfo
   JStringRef gameSpecificMessageRef{env, gameSpecificMessage};
 
   HAL_MatchInfo halMatchInfo;
-  std::snprintf(halMatchInfo.eventName, sizeof(halMatchInfo.eventName), "%s",
-                eventNameRef.c_str());
-  std::snprintf(reinterpret_cast<char*>(halMatchInfo.gameSpecificMessage),
-                sizeof(halMatchInfo.gameSpecificMessage), "%s",
-                gameSpecificMessageRef.c_str());
+  wpi::format_to_n_c_str(halMatchInfo.eventName, sizeof(halMatchInfo.eventName),
+                         "{}", eventNameRef.str());
+  wpi::format_to_n_c_str(
+      reinterpret_cast<char*>(halMatchInfo.gameSpecificMessage),
+      sizeof(halMatchInfo.gameSpecificMessage), "{}",
+      gameSpecificMessageRef.str());
   halMatchInfo.gameSpecificMessageSize = gameSpecificMessageRef.size();
   halMatchInfo.matchType = (HAL_MatchType)matchType;
   halMatchInfo.matchNumber = matchNumber;