Add new hook for specifying config per forward model step

[berland]

Issue
Resolves #9036

Approach
➕

• 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 'pytest tests/ert/unit_tests -n logical -m "not integration_test"')

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

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 86.36364% with 3 lines in your changes missing coverage. Please review.

Project coverage is 90.86%. Comparing base (cbaaca9) to head (859ec5d).
Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
src/ert/plugins/plugin_manager.py	84.21%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9050      +/-   ##
==========================================
+ Coverage   90.84%   90.86%   +0.02%     
==========================================
  Files         352      352              
  Lines       21746    21783      +37     
==========================================
+ Hits        19755    19793      +38     
+ Misses       1991     1990       -1     

Flag	Coverage Δ
cli-tests	38.99% <22.72%> (-0.02%)	⬇️
gui-tests	72.51% <22.72%> (-0.07%)	⬇️
performance-tests	49.48% <22.72%> (-0.03%)	⬇️
unit-tests	79.62% <86.36%> (+0.02%)	⬆️

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