Refactor and align Model initialization functions

[vers-w]

Feature type

Changing existing functionality

Improvement Description

The model initialization functions of model types sbm, sbm_gwf and sediment contain quite some duplicate code (after refactoring, see also issues #486 and #382, and PR #517).

Additionally, the model type sediment makes after refactoring (PR #463) use of LandGeometry and RiverGeometry types to store land and river shared geometry parameters, while for the sbm and sbm_gwf model types these parameters are stored as part of the Model.network and river and overland flow parameter sets. Model types sbm and sbm_gwf can also make use of these geometry types, where these structs are preferably stored at the same level in the Model struct for the different model types.

Implementation Description

No response

Additional Context

No response