refactor(reorg): extract survey + benchmark modules [8/10]

[valentijnscholten]

Stacked PRs

This is one of a stacked series that reorganizes dojo/ into self-contained dojo/{module}/ packages (matching the dojo/url/ reference). They are stacked — each PR is based on the previous one — so review and merge bottom-up in this order:

1. refactor(product_type): Extra ProductType models into dojo/product_type/ module [1/10] #14970 — product_type
2. refactor(test): Extract Test models into dojo/test/ module [2/10] #14971 — test
3. refactor(engagement): Extract Test models into dojo/test/ module [3/10] #14972 — engagement
4. refactor(product): Extract Product module into dojo/product/ [4/10] #14973 — product
5. refactor(finding): Reorganize finding into self-contained dojo/finding/ package [5/10] #14974 — finding (+ CWE & BurpRawRequestResponse fold-in)
6. refactor(reorg): extract user + system_settings modules [6/10] #14981 — peripheral: user + system_settings
7. refactor(reorg): extract endpoint + tool_type/tool_config/tool_product modules [7/10] #14982 — peripheral: endpoint + tool_type/tool_config/tool_product
8. refactor(reorg): extract survey + benchmark modules [8/10] #14983 — peripheral: survey + benchmark ◀ this PR
9. refactor(reorg): extract notes/note_type/file_uploads/reports/risk_acceptance [9/10] #14986 — peripheral: notes/note_type + file_uploads + reports + risk_acceptance
10. refactor(reorg): extract regulations/banner/announcement/development_environment/object [10/10] #14987 — peripheral: regulations + banner + announcement + development_environment + object

Merge #14970 first; each following branch is rebased onto the updated base and merged in turn. This PR continues the stack on top of #14982 — full implementation brief is the Phase 10 section in AGENTS.md.

Summary

Reorganizes the survey and benchmark domains into self-contained dojo/survey/ and dojo/benchmark/ packages with a ui/ sub-package, matching the dojo/url/ reference layout. Neither domain has any api_v2 serializers/viewsets, so there is no api/ layer (Phases 6–9 skipped). Pure code-movement: no behaviour or migration changes; backward-compat re-exports keep external consumers working.

benchmark (dojo/benchmark/)

• Move Benchmark_Type, Benchmark_Category, Benchmark_Requirement, Benchmark_Product, Benchmark_Product_Summary into dojo/benchmark/{models,admin}.py. All FKs use string refs; Benchmark_Requirement.cwe_mapping references "dojo.CWE" (CWE lives in dojo/finding/, re-exported from dojo.models).
• Move the benchmark forms into ui/forms.py (re-exported from dojo/forms.py for external consumers). Move views.py/urls.py into ui/; signals.py stays.

survey (dojo/survey/)

• Move the polymorphic question/answer/survey models (Question, TextQuestion, Choice, ChoiceQuestion, Engagement_Survey, Answered_Survey, General_Survey, Answer, TextAnswer, ChoiceAnswer) into dojo/survey/{models,admin}.py. The Question and Answer base classes keep their with warnings.catch_warnings(action="ignore", category=ManagerInheritanceWarning): wrapping. All FKs use string refs; get_form() lazy-imports the question forms from dojo.survey.ui.forms.
• Move the questionnaire/question/answer forms into ui/forms.py (including the survey-specific MultiWidgetBasic/MultiExampleField and the now-single-sourced MultipleSelectWithPop widget, removed as dead code from dojo/forms.py), and QuestionnaireFilter/QuestionTypeFilter into ui/filters.py. Move views.py/urls.py into ui/.