Refactor project structure

[mbruns91]

Fundamental changes to the project's structure.
I've opened the PR mainly to let the CI already run. There are definetely bugs and inconsistencies in the code at this point!
addresses #5 and #3
TODOS (could be extended or reduced at any point):

• get rid of pandas.DataFrame as response type from SPARQL queries

[github-actions]

👈 Launch a binder notebook on branch pyiron/courier/refactor_project_structure

[codecov]

Codecov Report

❌ Patch coverage is 40.54054% with 154 lines in your changes missing coverage. Please review.
✅ Project coverage is 40.90%. Comparing base (da61304) to head (7550cb8).

Files with missing lines	Patch %	Lines
courier/services/ontodocker/_compat.py	18.91%	30 Missing ⚠️
courier/services/ontodocker/datasets.py	30.00%	28 Missing ⚠️
courier/services/ontodocker/sparql.py	38.23%	21 Missing ⚠️
courier/http/url.py	17.39%	19 Missing ⚠️
courier/http/request.py	27.27%	16 Missing ⚠️
courier/base_client.py	50.00%	14 Missing ⚠️
courier/services/ontodocker/endpoints.py	52.63%	9 Missing ⚠️
courier/exceptions.py	70.00%	6 Missing ⚠️
courier/http/session.py	33.33%	4 Missing ⚠️
courier/services/ontodocker/client.py	60.00%	4 Missing ⚠️
... and 1 more

Additional details and impacted files

@@             Coverage Diff             @@
##             main       #7       +/-   ##
===========================================
+ Coverage   13.21%   40.90%   +27.69%     
===========================================
  Files           2       16       +14     
  Lines         174      264       +90     
===========================================
+ Hits           23      108       +85     
- Misses        151      156        +5     

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