Data Sources panel for Sahara

The Data Sources panel allows for the creation
of data sources that can eventually be used
as input and output for Elastic Data Processing
jobs.
This code was originally from:
https://github.com/openstack/sahara-dashboard

Change-Id: I61f5522755de6adcdef4c2f3ce61101918e2768a
Partial-Implements: blueprint merge-sahara-dashboard
Co-Authored-By: Nikita Konovalov <nkonovalov@mirantis.com>
Co-Authored-By: Dmitry Mescheryakov <dmescheryakov@mirantis.com>
Merge "Data Sources panel for Sahara"