Change component interface name ISystemChat to SystemChat (#995)
Change component interface name ISystemChat to SystemChat (#995)

* Change component name ISystemChat to SystemChat

ISystemChat was defined twice leading to issues

* Add system param to IChatMessage

FaridSafi/react-native-gifted-chat,FaridSafi/react-native-gifted-messenger,FaridSafi/react-native-gifted-chat,FaridSafi/react-native-gifted-messenger