[timeseries] Add initial support for second timeseries db

[PabloCastellano]

Related: #65, #66

Allow saving and querying the metrics from the second timeseries db.

• Add second timeseries db to docker-compose.yml
• Provide basic configuration for users
• Implement queries for the second timeseries db
• Document how to enable the second timseries db

[nemesifier]

As discussed today, after our research, Elasticsearch seems like a good option and we'll explore that.