Moved ContainerModel to Interfaces + replace all components to purecomponent (#12)

Reviewed-on: https://git.siklos-chaneru.duckdns.org/Siklos/svg-layout-designer-react/pulls/12

src/Components/Properties/Properties.tsx

@@ -6,20 +6,7 @@ interface IPropertiesProps {
   onChange: (key: string, value: string) => void
 }
 
-interface IPropertiesState {
-  hasUpdate: boolean
-}
-
-export class Properties extends React.Component<IPropertiesProps, IPropertiesState> {
-  public state: IPropertiesState;
-
-  constructor(props: IPropertiesProps) {
-    super(props);
-    this.state = {
-      hasUpdate: false
-    };
-  }
-
+export class Properties extends React.PureComponent<IPropertiesProps> {
   public render() {
     if (this.props.properties === undefined) {
       return <div></div>;