[FEATURE] Add grid reinforcement methods

[khelfen]

This issue is part of #15

Is your feature request related to a problem? Please describe.
At the moment the grid reinforcement is very simplified and sometimes produces unreasonable results such as very many parallel lines.

Describe the solution you'd like

• There should be more reinforcement methods available. See the dena Verteilnetzstudie for more information
  • grid separation
  • switch balancing
  • ...
• A methodology needs to be added to determine when which grid reinforcement method should be used.