ENYO-3616: choose file path with fileChooser on src attribute

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-3616 

- broken path is indicated by a icon except if the path starts with "http"
- path is broken if it doesn't start with "./" 

Enyo-DCO-1.1-Signed-off-by: Olga Popova <olga.popova@hp.com>