Bug 1505 - Provide test coverage for binding-data-codec using
sal-test-model

* added test yang modules to bindig-test-model
* added tests for serialization/deserialization of normalized nodes and
paths to binding-data-codec

Change-Id: Ibdf24dd9e51281be488fb40481a79d6f086a2115
Signed-off-by: Jan Hajnar <jhajnar@cisco.com>
Merge "Bug 1505 - Provide test coverage for binding-data-codec using sal-test-model"