Fix Swagger discrepancies

[jamesliupenn]

Fix Swagger discrepancies

Summary

• Changed all four vehicle endpoints (/latest-index-key, /index-keys, /objects, /latest-object) from POST to GET in
  the router registration which was returning 405 Not Allowed previously
• Replaced the opaque searchParams struct annotation with explicit, individually documented query parameters (id,
  type, source, producer, before, after, limit) across all four handlers
• Fixed tokenId path parameter type from string to integer in all handler annotations
• Reordered parameters in the generated Swagger docs so tokenId (path param) appears first, followed by query
  params in a logical order
• Added @Security BearerAuth annotation to all four endpoints, which was missing and caused the endpoints to appear
  as unauthenticated in the Swagger UI
• Added descriptions to before (Upper time bound (RFC3339)) and after (Lower time bound (RFC3339)) to clarify their
  expected format