Merge marker used for simulation fw models in Everest and Ert

[StephanDeHoop]

Issue
Resolves #8859

Approach
Merge the markers in Everest to the ones we use in Ert for when the eclipse simulator is not available.

(Screenshot of new behavior in GUI if applicable)

• 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

All modified and coverable lines are covered by tests ✅

Project coverage is 91.59%. Comparing base (45b9a36) to head (7c11bfc).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8978      +/-   ##
==========================================
+ Coverage   91.57%   91.59%   +0.01%     
==========================================
  Files         345      345              
  Lines       21302    21302              
==========================================
+ Hits        19507    19511       +4     
+ Misses       1795     1791       -4     

Flag	Coverage Δ
cli-tests	39.72% <ø> (+<0.01%)	⬆️
gui-tests	73.51% <ø> (ø)
performance-tests	50.30% <ø> (+0.02%)	⬆️
unit-tests	80.33% <ø> (+<0.01%)	⬆️

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[yngve-sk]

lgtm