Omnikdatalogger

This release improves the way data to pvoutput is supplied when you have a multiple inverter setup.
The DSMR section no longer needs a `plant_id`. Without `plant_id` in the DSMR terminal config, DSMR data will be automatically linked to the combined inverter data.

The `local_proxy` client plugin `hassapi` now also can read the `logger_entity` attribute from plant specific settings, to support multiple inverters. The `plant_id_list` attribute will be the base for the configuration.

Further:
- For those who want to want a develop environment, the use of a devcontainer now is supported including the ability to test a `hassapi` based setup.
- All source code now has been formatted using black.
- pvoutput needs no sys_id if it is specified at the plant specific settings.

This new release affects docker containers built.
Important is that config files now are placed in the `/config` container.
Make sure you check your config if you have problems using the new docker builds.

This release no longer ships omnikdataloggerproxy with omnikdatalogger releases.
The omnikdataloggerproxy script has been moved to https://github.com/jbouwh/omnikdataloggerproxy