fix: relabel finding Asset-tag (AND) filter to v3 Asset vocabulary

[stevewallone]

Description

The v3 Product→Asset relabel (#13155) centralises filter copy in dojo/asset/labels.py, gated by ENABLE_V3_ORGANIZATION_ASSET_RELABEL (default on). The Asset-level AND tag filter on the finding list (test__engagement__product__tags_and in FindingTagFilter) was left with a hardcoded "Product Tags (AND)" label and help text, so it kept the legacy wording even with the relabel enabled — inconsistent with:

• its siblings Test Tags (AND) / Engagement Tags (AND), and
• the OR variant, whose label is already set dynamically to Tags (Asset).

This wires the AND field to the edition-aware labels by adding ASSET_FILTERS_TAGS_ASSET_AND_LABEL and ASSET_FILTERS_TAGS_ASSET_AND_HELP to both vocabulary branches, so the field renders:

• v3: Asset Tags (AND) — help text "Filter Findings by the selected Asset tags (AND logic)"
• legacy edition: Product Tags (AND) — unchanged

The OR variant (test__engagement__product__tags) is intentionally left untouched: its label is set dynamically at render time by get_tags_label_from_model() → Tags (Asset), which already overrides any static declaration.

Test results

Adds a regression test unittests/test_filter_asset_tag_labels.py that asserts the rendered FindingFilter form field (not the static declared label=, which the dynamic setter can override) carries the Asset vocabulary. Verified RED→GREEN, and the surrounding filter/label unit tests pass. manage.py makemigrations --check is clean — no model or migration changes.

Documentation

The one docs screenshot that shows this label (OS__tagging_objects.md, "Filtering for Tags") is refreshed in a separate, dependent docs PR against dev. No doc changes here.

Checklist

• Bugfix submitted against the bugfix branch (branch is on the current bugfix tip).
• Meaningful PR name for release notes.
• Ruff compliant.
• Python 3.13 compliant.
• No model changes / migrations (verified makemigrations --check).
• Unit tests added.
• Categorised as a bugfix — please add the bugfix label (fork PRs can't set labels).