Navigates the view back one page.
Example
async function navigateBack() {
    const view = await fin.View.wrap({ name: 'testapp-view', uuid: 'testapp' });
    await view.navigate('https://www.google.com');
    return await view.navigateBack();
}
navigateBack().then(() => console.log('Navigated back')).catch(err => console.log(err));