Remove cookiecutter

[timmens]

• Remove cookiecutter
• Merge inner and outer layer of the project
• Switch to new pytask syntax
• Use hatch for package building
• Add Python 3.12 to test matrix
• Update visualization tasks for docs
• Update documentation
• Plot R results in python (read rds file from python)

What remains to be done in other PRs:

• Update the data management code

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (eda143b) to head (e75d584).

Additional details and impacted files

@@             Coverage Diff              @@
##             main      #149       +/-   ##
============================================
+ Coverage   58.49%   100.00%   +41.50%     
============================================
  Files           3        10        +7     
  Lines         159       141       -18     
============================================
+ Hits           93       141       +48     
+ Misses         66         0       -66     

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[hmgaudecker]

Looks great, thanks a lot! Two things:

1. We should add a test to the pipeline that runs pytask (call it test_template.py and include it among the list of things to delete right away)
2. In docs_template/source/getting_started/customising_the_template.md, please rearrange and adjust. First step needs to be to search for template_project in the entire codebase and replace with a valid Python object identifier. Otherwise, everyone will have a template_project environment, which will be confusing to people. And instead of "Review and update the following files...", we should again give precise instructions of what to search for and what to replace that by. I am thinking of a table like this one.

Almost done, thanks!!!