Add __str__ to remaining studies models

[danlamanna]

Annotation, StudyTask, Response, and Markup all rendered as " object (pk)" in the admin, including in list_display columns and inlines. Every other model in the app already defines str.

Markup's list_display renders the annotation, so select_related the relations that Annotation.str now traverses.

Summary by CodeRabbit

• Improvements
  • Enhanced administrative views for markup records by loading related study, image, annotation, and annotator details more efficiently.
  • Added clearer labels for annotations, markups, responses, and study tasks, making records easier to identify and interpret.
  • Markups now indicate whether each feature is present or absent, while responses display the associated question and selected value.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: dd76fc8a-b400-41fd-8975-63857a1c4760

📥 Commits

Reviewing files that changed from the base of the PR and between 2bc48f2 and b38371b.

📒 Files selected for processing (5)

• isic/studies/admin.py
• isic/studies/models/annotation.py
• isic/studies/models/markup.py
• isic/studies/models/response.py
• isic/studies/models/study_task.py

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📝 Walkthrough

Walkthrough

The PR adds formatted string representations to four study models and updates MarkupAdmin to eager-load related feature and annotation objects in its queryset.

Changes

Study administration and model display

Layer / File(s)	Summary
Model string representations isic/studies/models/annotation.py, isic/studies/models/markup.py, isic/studies/models/response.py, isic/studies/models/study_task.py	Annotation, Markup, Response, and StudyTask now provide formatted string values based on their related data.
Markup admin queryset isic/studies/admin.py	MarkupAdmin.get_queryset preserves the base queryset and eager-loads the markup feature and annotation relationships.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: brianhelba

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: adding str methods to the remaining studies models.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch studies/model-str

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