Replace react-loadable with Suspense/lazy

[brianlove]

react-loadable is no longer being updated and uses deprecated React functions. Replace it with Suspense/lazy (see https://github.com/georgetown-cset/science_map_ui/pull/580).

    console.warn
      Warning: componentWillMount has been renamed, and is not recommended for use. See https://reactjs.org/link/unsafe-component-lifecycles for details.
      
      * Move code with side effects to componentDidMount, and set initial state in the constructor.
      * Rename componentWillMount to UNSAFE_componentWillMount to suppress this warning in non-strict mode. In React 18.x, only the UNSAFE_ name will work. To rename all deprecated lifecycles to their new names, you can run `npx react-codemod rename-unsafe-lifecycles` in your project source folder.
      
      Please update the following components: LoadableComponent

      53 |     // Click on an input node to show its documentation
      54 |     expect(screen.getAllByText("Crystal growing furnaces").length).toEqual(1);
    > 55 |     fireEvent.click(screen.getByText("Crystal growing furnaces"));
         |               ^
      56 |     expect(screen.getAllByText("Crystal growing furnaces").length).toEqual(3);
      57 |
      58 |     // Click on another node inside the documentation panel