kueue: add AdmissionCheck list and detail views

[Thesmoothengineer]

What this PR does

Adds a new AdmissionCheck resource to the Kueue plugin, following the existing patterns used
by ClusterQueue, LocalQueue, ResourceFlavor, and Workload. Previously, AdmissionCheck
and ProvisioningRequestConfig were the only Kueue CRDs with no dedicated views in this plugin.

• Adds src/resources/admissionCheck.ts — a KubeObject-based resource class typed against
  the real AdmissionCheckSpec/AdmissionCheckStatus fields (controllerName, parameters,
  conditions), per the Kueue API reference.
• Adds src/resources/admissionCheckFormatters.ts with exported, documented, pure functions:
  renderControllerName, renderParameters, renderAdmissionCheckStatus.
• Adds src/resources/admissionCheck.test.ts with unit tests covering each formatter,
  including empty/undefined edge cases.
• Adds src/components/admissionchecks/List.tsx and Detail.tsx, mirroring the
  resourceflavors components structure (cluster-scoped, using KueueAdminResourceAccess
  and ResourceListView/DetailsGrid).
• Registers the sidebar entry and routes in index.tsx and utils/kueueRoutes.ts.

Testing

• npm run test — all 44 tests pass (10 new).
• npm run build — builds cleanly.
• Verified locally in a running Headlamp instance against a kind cluster: applied a real
  AdmissionCheck resource and confirmed both the List and Detail views render its
  controller, parameters, and status correctly, and the empty-list state renders without
  errors when no AdmissionChecks exist.

Why

AdmissionCheck is a core Kueue resource referenced directly by ClusterQueue's
admissionChecksStrategy, but had no dedicated view yet. This is a small, additive,
low-risk addition that gives users visibility into admission checks without touching any
existing resource types.

[Thesmoothengineer]

Closing this in favor of #1174, which I noticed was already open and covers the same AdmissionCheck resource in more depth (including i18n and a conditions section). Will look for a different area to contribute to next.