Use natsort to sort the produced csv rows from gather_summary_observations

[SAKavli]

Issue
Resolves #13665

Approach
I believe this is ready to go unless I have misunderstood the prioritization of the sorting.

The code natsorts on the complete string, but perhaps it is more sensible to sort based on well names first, then summary keyword?

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.34%. Comparing base (3fb9cab) to head (44ca2e7).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13684      +/-   ##
==========================================
- Coverage   89.39%   89.34%   -0.05%     
==========================================
  Files         469      469              
  Lines       33406    33420      +14     
==========================================
- Hits        29862    29859       -3     
- Misses       3544     3561      +17     

Flag	Coverage Δ
cli-tests	35.78% <100.00%> (-0.05%)	⬇️
fuzz	43.37% <33.33%> (-0.05%)	⬇️
gui-tests	59.25% <33.33%> (-0.06%)	⬇️
performance-and-unit-tests	77.79% <100.00%> (-0.05%)	⬇️
test	44.91% <0.00%> (-0.06%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/ert/gather_summary_observations.py	79.66% <100.00%> (+0.08%)	⬆️

... and 6 files with indirect coverage changes

[Copilot]

Pull request overview

This PR updates convert_summary_observations (used by the gather_summary_observations CLI flow) to output CSV rows in a natural sort order (e.g., OP2, OP4, OP10, OP30) rather than preserving dict insertion order, addressing the ordering issue described in #13665.

Changes:

• Sort CSV output rows by summary key using natsort.natsorted(...).
• Add a unit test that asserts natural ordering of generated CSV rows for well keys containing numbers.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/ert/gather_summary_observations.py	Iterate summary keys using natsorted(...) to produce naturally ordered CSV rows.
tests/ert/unit_tests/cli/test_gather_summary_observations.py	Add regression test verifying natural sort order in the produced CSV.

[codspeed-hq]

Merging this PR will not alter performance

✅ 36 untouched benchmarks

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_{Comparing SAKavli:natsort-csv-columns (44ca2e7) with main (9643008)}

[Copilot]

Pull request overview

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.