title: how to make sure that sap.m.select is filled with data
body: <p>I have a sap.m.select that is loaded with data in the beggining of the app.
  I can only proceed forward if the select control contains data.
  I want to make sure that the data is loaded and then enable a button "Go".</p>
  
  <p>I checked that a list control has "attachUpdateFinished". Do we have something similar for select.
  or is there any other way i can do it?</p>
  
  <p>Thanks in Advance.</p>