Phase Stats Providers

[ArneTR]

This PR refactors the phase_stats to use a plug-in mechanism.

Concept:

• A new class is created in config.yml: Phase Stats Provider

• This can then define an input that it swallows

• and an output that it emits.

• The provider will then take the input and aggregate it and create an average value

• It needs a name as output

• And the provider can also multiply by a fixed value

• The system gets one or more inputs

  • It can then aggregate these itself, or spit out something per value again

~~Translated with DeepL.com (free version)~~

Note: This PR is a draft and might not come into action in this form. It is public only to track and save progress on Github