Smartmeter-datacollector-configurator

**Improvements**
* clarify the meaning of the different passwords
* automatically restart the `python3-smartmeter-datacollector` when deploying the configuration
* add unit tests

**Features**
* Support building Debian packages
* Add `build-deb.yml` GitHub workflow to automatically build Debian packages for
* Debian Buster amd64
* Raspberry Pi OS (Buster) armhf

**Bug Fixes**
* properly attach / upload the Python build artifacts to a newly created release in the `publish-to-pypi.yml` GitHub workflow

Initial release of `smartmeter-datacollector-configurator` tool which supports
* creating / modifying a valid configuration for [`smartmeter-datacollector`](https://github.com/scs/smartmeter-datacollector)
* restarting `smartmeter-datacollector`
* optionally controlling a demo of `smartmeter-datacollector` which includes an MQTT broker, Telegraf, InfluxDB and Grafana

**ATTENTION:** `smartmeter-datacollector-configurator` is still in **beta** phase!