Add initialization method from flows for LCT model

[lenaploetzke]

Feature description

Initialization method with flows for lct model, initialization method from IDE model. Can be used to generate consistent initial numbers for LCT and IDE model.

Additional context

Code can be copied from #680 Files:

• cpp/models/lct_secir/initialization.cpp
• cpp/tests/test_lct_initializer.cpp
• add example?

Checklist

• [X] Attached labels, especially loc:: or model:: labels.
• [X] Linked to project.