Study and implement a basic API to explore a domain based on the tags associated with the SmartDataContext of the domain.

For version v0 the following features should be implemented:

• Study, develop and implement a representation/storage of tag information for each domain - iot/discovery-backend#2
• Develop support to automatically update the tag-related information of the domains -iot/datalake-unstructured#9
• Implement a discovery API that returns information to build a cloud-tag visualization of a domain, from which a user can find SmartDataSources and/or series associated to one or more tags - iot/discovery-backend#3
• Write the implementation report