ArduinoJson 7.2.0 * Store object members with two slots: one for the key and one for the value * Store 64-bit numbers (`double` and `long long`) in an additional slot * Reduce the slot size (see table below) * Improve message when user forgets third arg of `serializeJson()` et al. * Set `ARDUINOJSON_USE_DOUBLE` to `0` by default on 8-bit architectures * Deprecate `containsKey()` in favor of `doc["key"].is<T>()` * Add support for escape sequence `\'` (issue #2124)