Join SimulationContext and BatchSimulatorContext

[oyvindeide]

• [x] PR title captures the intent of the changes, and is fitting for release notes.
• [x] Added appropriate release note label
• [x] Commit history is consistent and clean, in line with the contribution guidelines.
• [x] Make sure tests pass locally (after every commit!)

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 92.52336% with 8 lines in your changes missing coverage. Please review.

Project coverage is 86.88%. Comparing base (abb9957) to head (2287bd8). Report is 2 commits behind head on main.

Files	Patch %	Lines
src/ert/simulator/batch_simulator_context.py	92.52%	8 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8229 +/- ## ======================================= Coverage 86.88% 86.88% ======================================= Files 379 378 -1 Lines 23972 23915 -57 Branches 634 618 -16 ======================================= - Hits 20828 20779 -49 + Misses 3070 3055 -15 - Partials 74 81 +7 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.