title: SearchBar in NavigationBar
body: <p>It's a bit difficult to explain my problem in one sentence so i'll put this two pictures here. <br/>
  I want this behaviour from my app. At first I got simple navigationBar with ButtonBarItems.
  <img src="https://i.stack.imgur.com/GRy7r.jpg" alt="navigation bar with 2 buttons"></p>
  
  <p>And after search button is clicked i want this behaviour:
  <img src="https://i.stack.imgur.com/MWZ2u.jpg" alt="search bar inside navigation bar"></p>
  
  <p>How to achieve this behaviour?
  I got up only with one idea - to create new view and place it , but it seems not like the best practice. </p>