Add structured validation error

[jrasko]

Description

Use structured errors to identify the faulty inputs and allow the frontend to make them visible to the user

Checklist

• Documentation updated (docstrings, READMEs, user guides, inline comments, doc folder updates etc.)
• Changes noted in release notes (if any)
• Consent to release this PR's code under the GNU Affero General Public License v3.0

[codecov]

Codecov Report

❌ Patch coverage is 75.60976% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.85%. Comparing base (c4a9d4b) to head (79c7902).
⚠️ Report is 82 commits behind head on main.

Files with missing lines	Patch %	Lines
assume/units/storage.py	72.72%	6 Missing ⚠️
assume/units/powerplant.py	60.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #745      +/-   ##
==========================================
+ Coverage   81.83%   81.85%   +0.01%     
==========================================
  Files          55       55              
  Lines        8280     8288       +8     
==========================================
+ Hits         6776     6784       +8     
  Misses       1504     1504              

Flag	Coverage Δ
pytest	81.85% <75.60%> (+0.01%)	⬆️

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[maurerle]

The rational behind this change is to support #705 and the assume-gui part.
This helps to have more information about which component causes a validation error in tools using assume (like the assume-gui).

[maurerle]

I would like to have every custom Exception in this File to inherit from AssumeException as well..?
You should inherit from both to not break existing catches of ValueError, but also align with the AssumeException idea.

[jrasko]

I still not get the idea of the Assume exception. What is its purpose (when should it be thrown)? To which use-case does this exception add value? We might use this opportunity to clarify and document this.