Rewrite Converter<float>

Before: 9802, 8558, 9630, 12418, 9654
After:  9802, 8486, 9630, 12418, 9654
Target: 9800, 8458, 9634, 12290, 9702

Author: bblanchon

src/ArduinoJson/Variant/ConverterImpl.hpp

@@ -113,9 +113,12 @@ template <typename T>
 struct Converter<T, detail::enable_if_t<detail::is_floating_point<T>::value>>
     : private detail::VariantAttorney {
   static bool toJson(T src, JsonVariant dst) {
-    auto variant = getVariantImpl(dst);
-    variant.clear();
-    return variant.setFloat(src);
+    auto data = getData(dst);
+    auto resources = getResourceManager(dst);
+    if (!data)
+      return false;
+    detail::VariantImpl::clear(data, resources);
+    return detail::VariantImpl::setFloat(src, data, resources);
   }
 
   static T fromJson(JsonVariantConst src) {