Make MQTT config common for all modules

[frederikheld]

AS an operator
I WANT TO have all config related to the common communication infrastructure in one place
SO THAT I don't need to spend time configuring each module with the same information.

Acceptance Criteria:

• Common config file for MQTT related settings
• File format that can be consumed by all modules (aka used languages)

Note: This US does not include that all modules need to be refactored to use this config, but the config has to be ready that each module can consume it!