Add wide character formatting and output support to wincolor_sink.

Fixes printing of unicode characters to the windows console such as microsecond suffix for std::chrono types.

include/spdlog/sinks/wincolor_sink-inl.h

@@ -134,19 +134,36 @@ void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::print_range_(const memory_buf_t
                                                              size_t start,
                                                              size_t end) {
     if (end > start) {
+    #if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+        wmemory_buf_t wformatted;
+        details::os::utf8_to_wstrbuf(string_view_t(formatted.data() + start, end - start),
+                                     wformatted);
+        auto size = static_cast<DWORD>(wformatted.size());
+        auto ignored = ::WriteConsoleW(static_cast<HANDLE>(out_handle_), wformatted.data(), size,
+                                       nullptr, nullptr);
+    #else
         auto size = static_cast<DWORD>(end - start);
         auto ignored = ::WriteConsoleA(static_cast<HANDLE>(out_handle_), formatted.data() + start,
                                        size, nullptr, nullptr);
+    #endif
         (void)(ignored);
     }
 }
 
 template <typename ConsoleMutex>
 void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::write_to_file_(const memory_buf_t &formatted) {
-    auto size = static_cast<DWORD>(formatted.size());
     DWORD bytes_written = 0;
+#if defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT)
+    wmemory_buf_t wformatted;
+    details::os::utf8_to_wstrbuf(string_view_t(formatted.data(), formatted.size()), wformatted);
+    auto size = static_cast<DWORD>(wformatted.size() * sizeof(WCHAR));
+    auto ignored = ::WriteFile(static_cast<HANDLE>(out_handle_), wformatted.data(), size,
+                               &bytes_written, nullptr);
+#else
+    auto size = static_cast<DWORD>(formatted.size());
     auto ignored = ::WriteFile(static_cast<HANDLE>(out_handle_), formatted.data(), size,
                                &bytes_written, nullptr);
+#endif
     (void)(ignored);
 }