[WiP] Improved configuration reading

## Context
The reading of the configuration is currently very tightly coupled to the execution of several parts of the system. Also, the configuration file is read to an array, which is very error prone and can be hard to scale.
The proposed solution is a model-based system for the configuration. The configuration can than be separated from the execution parts.

## Tasks
[X] Wrapped the yaml configuration in a model
[X] Introduced events to handle parts of the configuration, such as notifications. This allows for even more flexibility
[X] Added Pimple, the dependency injection container
[ ] Let Pimple handle the configuration reading and just inject the model where necessary