Combine error and warning boxes that have the same message

[eivindjahren]

Resolves #8151

Screencast from 2024-06-14 12-03-22.webm

• [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
• [x] 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 79.72973% with 15 lines in your changes missing coverage. Please review.

Project coverage is 86.58%. Comparing base (77fa511) to head (b6dd0fb). Report is 6 commits behind head on main.

Files	Patch %	Lines
src/ert/gui/suggestor/_suggestor_message.py	75.00%	15 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8154 +/- ## ========================================== + Coverage 76.93% 86.58% +9.64% ========================================== Files 383 384 +1 Lines 23813 23883 +70 Branches 625 636 +11 ========================================== + Hits 18320 20678 +2358 + Misses 5412 3132 -2280 + Partials 81 73 -8 ```

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