Fix None child state rendering in UI

[Codingaditya17]

Summary

This PR fixes rendering for serialized None child state keys in the UI.

The grid API can return child states like {"None": 2, "success": 1}. Before this change, the UI used the raw None key directly for Chakra color tokens and translations, producing None.solid and common:states.None.

This change adds small state normalization helpers and applies them to the two direct child_states render sites:

• SegmentedStateBar.tsx
• TaskInstanceTooltip.tsx

Scope

This PR intentionally only fixes the direct child state breakdown/rendering issue described in #67541. It does not change the dominant state logic handled separately in #67543.

Tests

pnpm vitest run src/utils/stateUtils.test.ts src/components/TaskInstanceTooltip.test.tsx



Test Files  2 passed (2)
Tests       21 passed (21)

[bbovenzi]

It would be better to fix this on the API level. Renaming None to none, and making sure that no_status & none share the same color in theme.ts and the same translation in common.json

[Codingaditya17]

Thanks for the review. I updated the PR to move the normalization to the API layer as suggested.

What changed:

• The grid API now serializes None child state keys as "none" instead of emitting "None".
• Updated the grid API response model to allow "none" as a child state key.
• Updated the existing grid API test expectations from "None" to "none".
• Removed the frontend-only "None" normalization helpers and restored the UI render sites to use the API-provided state key directly.
• Added no_status in theme.ts with the same gray semantic tokens as none.

Tests run locally:

• uv run pytest airflow-core/tests/unit/api_fastapi/core_api/routes/ui/test_grid.py -k "mapped"
  Result: 1 passed, 59 deselected
• cd airflow-core/src/airflow/ui && pnpm vitest run src/utils/stateUtils.test.ts src/components/TaskInstanceTooltip.test.tsx
  Result: Test Files 2 passed, Tests 17 passed
• uv run prek run ts-compile-lint-ui --all-files
  Result: Compile / format / lint UI Passed