Set ensemble size from design matrix

[larsevj]

Also changes the wording in the GUI from Number of realizations to Ensemble size

Changes in gui:

• PR title captures the intent of the changes, and is fitting for release notes.
• Added appropriate release note label
• Commit history is consistent and clean, in line with the contribution guidelines.
• Make sure unit tests pass locally after every commit (git rebase -i main --exec 'just rapid-tests')

When applicable

• When there are user facing changes: Updated documentation
• New behavior or changes to existing untested code: Ensured that unit tests are added (See Ground Rules).
• Large PR: Prepare changes in small commits for more convenient review
• Bug fix: Add regression test for the bug
• Bug fix: Create Backport PR to latest release

[codspeed-hq]

CodSpeed Performance Report

Merging #10406 will not alter performance

_{Comparing larsevj:set_ensemble_size_from_design_matrix (78da766) with main (97e4b3a)}

Summary

✅ 25 untouched benchmarks

[larsevj]

Hover info (on mac):

[oyvindeide]

Tested this, and got some strange behavior, I have this design matrix in the poly example:

REAL | a | b
   0 | 0 | 2
   1 | 0 | 2
   2 | 0 | 2
   3 | 0 | 2

then I start ert and select Ensemble experiment, immediately the Ensemble size shows what I would expect, with the warning, however if I decrease the active realizations from 0-3 -> 0-2, Ensemble size jumps to 100, I would expect 3.

[larsevj]

Tested this, and got some strange behavior, I have this design matrix in the poly example:

REAL | a | b
   0 | 0 | 2
   1 | 0 | 2
   2 | 0 | 2
   3 | 0 | 2

then I start ert and select Ensemble experiment, immediately the Ensemble size shows what I would expect, with the warning, however if I decrease the active realizations from 0-3 -> 0-2, Ensemble size jumps to 100, I would expect 3.

This should be fixed now ( for ensemble experiment), not sure what to do with the warning label though it will currently only be set if the ensemble_size is different on initialization.