Add max_memory keyword to the Everest config

[verveerpj]

Issue
Resolves #10624
Resolves #9569

Approach
Add the keyword, add to generated ert config

(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 '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: Add backport label to latest release (format: 'backport release-branch-name')

[codspeed-hq]

CodSpeed Performance Report

Merging #10637 will not alter performance

_{Comparing add-max_memory (c336dae) with main (9599946)}

Summary

✅ 25 untouched benchmarks

[oyvindeide]

Looks good, I have one question that is slightly more work, but think it might be worth it in the long run, not sure what you think?

[oyvindeide]

LGTM!