PMU data visualization example using Kafka and TimescaleDB

[nikolasyugi]

This PR adds an example deployment for the PMU data visualization based on Kafka (strimzi), TimescaleDB and Grafana.

[m-mirz]

@Haifischbecken This might be interesting for your upcoming work related to kafka.

[Haifischbecken]

@m-mirz do you know whether there was any decision regarding InfluxDB or Timescale etc.
In the MQTT based setup we used InfluxDB, was there a reason to change it in this setup?

[Haifischbecken]

@nikolasyugi When looking over the pull request I noticed that it includes docker login secret. After decoding it it does not seem to be an actual login. Luckily looks like there was a syntax error on creation, encoding the PATH to the login file instead of the login file. Secrets should never be pushed since it very difficult to remove them from the commit history. As this secret does not appear to include login credential it should be save to just remove before merging.

[m-mirz]

@Haifischbecken we wanted to try out timescaledb as alternative to influx because postgres is more community driven.