Rethink create_model input handling.

[lnksz]

Now create_model changes the input parameters data, edge, vertex directly.
This is kind of a tolerable side-effect until these are not reused after the specific run.

Changes:

• data dict gets extended with hubs, vertex and edge keys.
• vertex and edge get reindexed.

Alternatives:

• Handle both formats. 🥇
• Do not have this side-effect and await the DataFrames in a well-defined format. 🥈
  • needs a review of the data preparation process at the beginning of create_model esp. at m.peak
• Operate on a local copy of the parameter and change it as it is now done.