Decompose openstack.yaml into data and schema

*User story:*
As a developer, I would like to be able to make changes to the openstack.yaml file which are relevant to the data without being forced to consider the UI implementation and vice versa.

*Description:*
openstack.yaml file should be split into two: one with data, and one with UI scheme how to show data. Data should be owned by library team (since it has deployment specific data, such as a set of network roles). UI schema should be owned by UI team.

*Acceptance criteria:*
Split openstack.yaml into two files - confirm how split will be performed with Library and UI team

*Possible Solution:*
Return pure data from Nailgun, and return data schema by calling a special endpoint.