Improve print order of state variables in settings module.

[sbrodehl]

Improve print order of state variables in settings module

This MR sorts state variables based on their (nested) module name in case-insensitive, alphabetical order, with parameters always on top.

Description

Setup:
Use settings module to print state variables.

Problem:
Some variables were hard to find between nested modules.

Previously:
Note the ** and <--, which are variables of different modules, which are not printed as a group.

d           = ...  **
sa│Aa│a     = ...
  │  │b     = ...
  │Ab       = ...  <--
  │D        = ...  <--
  │L│a      = ...
  │ │b      = ...
  │M        = ...  <--
  │Sa│a     = ...
  │  │ba    = ...
  │  │bb│ta = ...
  │  │  │tb = ...
  │Sb       = ...  <--
  │Sca│a    = ...
  │   │b    = ...
  │Scb│a    = ...
  │   │b    = ...
  │Ta       = ...  <--
  │Tb│m     = ...
  │ │n      = ...
  │a        = ...  <--
sb          = ...  **
v           = ...  **

New Behavior:

d           = ...  **
sb          = ...  **
v           = ...  **
sa│a        = ...  <--
  │Ab       = ...  <--
  │D        = ...  <--
  │M        = ...  <--
  │Sb       = ...  <--
  │Ta       = ...  <--
sa│Aa│a     = ...
  │  │b     = ...
  │L│a      = ...
  │ │b      = ...
  │Sa│a     = ...
  │  │ba    = ...
  │  │bb│ta = ...
  │  │  │tb = ...
  │Sca│a    = ...
  │   │b    = ...
  │Scb│a    = ...
  │   │b    = ...
  │Tb│m     = ...
  │ │n      = ...

Things done in this MR

• Create tree of state variables, sorts parameters and modules separately, and first list parameters, then sorted modules.

Check all before creating this PR:

• Documentation adapted
• unit tests adapted / created

Example Usage

Use the settings module to list state variables.

[da-h]

Great improvement of readability of the output!

Thanks for making this project better for everyone. 👍 🚀