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.

ntcore/src/main/native/cpp/net/ClientImpl.cpp

@@ -171,7 +171,7 @@ void CImpl::ProcessIncomingBinary(std::span<const uint8_t> data) {
 }
 
 void CImpl::HandleLocal(std::vector<ClientMessage>&& msgs) {
-  DEBUG4("{}", "HandleLocal()");
+  DEBUG4("HandleLocal()");
   for (auto&& elem : msgs) {
     // common case is value
     if (auto msg = std::get_if<ClientValueMsg>(&elem.contents)) {

ntcore/src/main/native/cpp/net/NetworkLoopQueue.cpp

@@ -45,7 +45,7 @@ void NetworkLoopQueue::SetValue(NT_Publisher pubHandle, const Value& value) {
   m_size += sizeof(ClientMessage);
   if (m_size > kMaxSize) {
     if (!m_sizeErrored) {
-      WPI_ERROR(m_logger, "{}", "NT: dropping value set due to memory limits");
+      WPI_ERROR(m_logger, "NT: dropping value set due to memory limits");
       m_sizeErrored = true;
     }
     return;  // avoid potential out of memory

ntcore/src/main/native/cpp/net/ServerImpl.cpp

@@ -758,7 +758,7 @@ void ClientDataLocal::SendPropertiesUpdate(TopicData* topic,
 }
 
 void ClientDataLocal::HandleLocal(std::span<const ClientMessage> msgs) {
-  DEBUG4("{}", "HandleLocal()");
+  DEBUG4("HandleLocal()");
   // just map as a normal client into client=0 calls
   for (const auto& elem : msgs) {  // NOLINT
     // common case is value, so check that first
@@ -2145,7 +2145,7 @@ void SImpl::UpdateMetaClients(const std::vector<ConnectionInfo>& conns) {
   if (mpack_writer_destroy(&w) == mpack_ok) {
     SetValue(nullptr, m_metaClients, Value::MakeRaw(std::move(w.bytes)));
   } else {
-    DEBUG4("{}", "failed to encode $clients");
+    DEBUG4("failed to encode $clients");
   }
 }
 

ntcore/src/main/native/cpp/net/WireDecoder.cpp

@@ -119,7 +119,7 @@ static void WireDecodeTextImpl(std::string_view in, T& out,
   }
 
   if (!j.is_array()) {
-    WPI_WARNING(logger, "{}", "expected JSON array at top level");
+    WPI_WARNING(logger, "expected JSON array at top level");
     return;
   }