added save_to_history to chat sample
added save_to_history to chat sample

QuickBlox/quickblox-javascript-sdk,mega5329/quickblox-javascript-sdk,SaniraX/quickblox-javascript-sdk,SaniraX/quickblox-javascript-sdk,mega5329/quickblox-javascript-sdk,QuickBlox/quickblox-javascript-sdk,mega5329/quickblox-javascript-sdk