[TIMOB-12818] BlackBerry: TextField blur and focus

Implement the blur and focus methods for TextFields.

Acceptance Test

var win = Ti.UI.createWindow(); var textfield = Ti.UI.createTextField(); win.add(textfield); textfield.addEventListener('focus', function() { Ti.API.info('focus'); }); textfield.addEventListener('blur', function() { Ti.API.info('blur'); }); setTimeout(function() { textfield.focus(); setTimeout(function() { textfield.blur(); }, 2000); }, 2000); win.open(); ``` 1. Wait a couple seconds after the app launches. 2. Verify the textfield automatically gains focus. There should also be a log "focus" printed. 3. Wait another couple seconds after focus. There should also be a log "blur" printed. 4. The textfield should have lost focus. 5. Try focusing the field by clicking on it. A log "focus" should be printed and the keyboard presented. 6. Blur the field by tapping elsewhere in the window (background). It should be blurred and a log "blur" printed.