Tests for evaluate script

[sfmig]

Rebase after #172 is merged.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 8.86076% with 72 lines in your changes missing coverage. Please review.

Project coverage is 36.53%. Comparing base (4e70c2c) to head (e87a57c).

Files	Patch %	Lines
crabs/detection_tracking/evaluate_model.py	0.00%	71 Missing :warning:
crabs/detection_tracking/visualization.py	85.71%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #199 +/- ## ========================================== - Coverage 37.75% 36.53% -1.23% ========================================== Files 20 20 Lines 1348 1404 +56 ========================================== + Hits 509 513 +4 - Misses 839 891 +52 ```

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[sfmig]

Closing because:

• edits to visualisation and visualisation tests have been covered in PR220
  • remaining bits are covered in #232
• other changes (such as config update) have also been implemented separately
• the branch is outdated for the skeleton tests added to be worth keeping