Catch unexpected exceptions and clean up to avoid hanging GUI

[BjarneHerland]

Resolves #3244

Approach
Prevent exceptions to pass the EvaluatorTracker as this seems to be able to freeze Qt.

Pre review checklist

• Added appropriate release note label
• PR title captures the intent of the changes, and is fitting for release notes.
• Commit history is consistent and clean, in line with the contribution guidelines.

[codecov-commenter]

Codecov Report

Merging #3315 (96dbc4f) into main (fc25cf2) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #3315      +/-   ##
==========================================
- Coverage   64.95%   64.94%   -0.02%     
==========================================
  Files         616      616              
  Lines       48273    48282       +9     
  Branches     4331     4331              
==========================================
  Hits        31356    31356              
- Misses      15474    15482       +8     
- Partials     1443     1444       +1     

Impacted Files	Coverage Δ
...rt/ensemble_evaluator/tracker/evaluator_tracker.py	72.22% <0.00%> (-2.99%)	⬇️
ert_gui/tools/plot/plot_api.py	80.00% <0.00%> (-2.36%)	⬇️
ert_data/measured.py	85.71% <0.00%> (-1.67%)	⬇️
libres/lib/res_util/block_fs.cpp	66.46% <0.00%> (-0.31%)	⬇️
ert_gui/gert_main.py	96.20% <0.00%> (ø)
ert_gui/about_dialog.py	20.68% <0.00%> (ø)
ert_gui/plottery/plot_style.py	97.75% <0.00%> (ø)
ert_gui/tools/file/file_dialog.py	17.72% <0.00%> (ø)
ert_gui/ertwidgets/caseselector.py	77.50% <0.00%> (ø)
ert_gui/tools/export/export_tool.py	54.54% <0.00%> (ø)
... and 4 more

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