Enable log macros to work with no args (#4475)

This is enabled by the C++20 __VA_OPT__ feature.
Uses of "{}" format string were updated.
Some warning suppressions were required for older clang versions.
Also improve codegen of wpi::Logger::Log(), frc::ReportError(), and frc::MakeError();
these generate better and less redundant code if they use fmt::string_view for the
format string instead of templating on it.

wpilibNewCommands/src/main/native/cpp/frc2/command/ParallelRaceGroup.cpp

@@ -50,7 +50,7 @@ void ParallelRaceGroup::AddCommands(
   }
 
   if (isRunning) {
-    throw FRC_MakeError(frc::err::CommandIllegalUse, "{}",
+    throw FRC_MakeError(frc::err::CommandIllegalUse,
                         "Commands cannot be added to a CommandGroup "
                         "while the group is running");
   }
@@ -62,7 +62,7 @@ void ParallelRaceGroup::AddCommands(
       m_runWhenDisabled &= command->RunsWhenDisabled();
       m_commands.emplace_back(std::move(command));
     } else {
-      throw FRC_MakeError(frc::err::CommandIllegalUse, "{}",
+      throw FRC_MakeError(frc::err::CommandIllegalUse,
                           "Multiple commands in a parallel group cannot "
                           "require the same subsystems");
     }