https://github.com/sendbird/sendbird-uikit-ios/releases/tag/v2.1.13
• Updated minor iOS version 10 to 11.
• Modified keyboard height logic when using isTranslucent=false option.
• Applied property-wrapper to theme properties.
• Removed logic that set theme to a global theme in the setupStyles, updateStyles functions.
• Added overlayTheme property to classes that use them differently depending on the overlay.
• Added messageInputView(_:didChangeText:) event to SBUMessageInputViewDelegate.
• Modified access level of SBUMessageStateView to open
• Added timeFormat which is type of String
• Added timeLabelCustomSize which is type of CGSize
• Modified access level of UI components to public
• Aded extensions of Date
• Added Date.DateFormat enum.
• Modified access level of Date sub_toString(formatString:localizedFormat:) -> String to public
