PM-5510: Add marathon submission test type filter

[jmgasper]

What was broken
Marathon Match submissions could only be filtered by general submission fields, so System, Provisional, and Example test rows stayed intermingled in the Work app submissions list.

Root cause
The submissions list already displayed the current marathon test process from review summation metadata, but that normalized process was not part of the filter state or filter predicate.

What was changed
Added a Marathon Match-only Test type select with All, System, Provisional, and Example options. The filter uses the existing getSubmissionTestProgress helper so the filter matches the same current test process shown in the table.

Any added/updated tests
Added SubmissionsSection coverage that verifies marathon submissions can be filtered by System and Example test types.

Validation run:

• PASS yarn test:no-watch --runTestsByPath src/apps/work/src/pages/challenges/ChallengeEditorPage/components/SubmissionsSection/SubmissionsSection.spec.tsx
• PASS yarn lint
• PASS yarn run build
• FULL SUITE RUN yarn test:no-watch currently fails on origin/dev unrelated areas, including engagement-editor.schema.spec.ts, PaymentFormModal.spec.tsx, and ChallengeEditorForm.spec.tsx.