refactor: separate stats endpoints into two, rename keys for more clarity

[bolinocroustibat]

Closes #382 and more.

1. Moved resource stats (total_count, deleted_count, statuses_count) from /api/status/crawler to /api/resources/stats. Kept total_eligible_count in crawler status (crawler-related and expensive).

   • More consistent perimeters for each stats endpoint (one related to ressources info, one related to crawler status)
   • That makes the endpoint /api/status/crawler less SQL-expensive and better balance the expensive queries between /api/status/crawler and /api/resources/status

2. Renamed status endpoint keys for clarity (fixes Rename and add keys/values in /api/status/crawler response for more clarity #382):

   • pending_count → needs_check_count
   • fresh_count → up_to_date_check_count
   • checked_percentage → needs_check_percentage
   • fresh_percentage → up_to_date_check_percentage

3. Added in_progress_count and in_progress_percentage

4. Performance optimization: Combined 2 SQL queries into 1 (reduced from 3 to 2 queries total in /api/status/crawler)

5. Renamed variable: total_resources_filtered → total_eligible_resources (and JSON key total_filtered_count → total_eligible_count)

6. Add tests for this new endpoint, adapt the test for /crawler/stats and add a new test case (outdated check)

How it looks

GET /api/resources/stats:

{
  "total_count": 100,
  "deleted_count": 3,
  "statuses_count": {
    "null": 85,
    "BACKOFF": 2,
    "CRAWLING_URL": 1,
    "TO_ANALYSE_RESOURCE": 0,
    "ANALYSING_RESOURCE_HEAD": 0,
    "DOWNLOADING_RESOURCE": 0,
    "ANALYSING_DOWNLOADED_RESOURCE": 0,
    "TO_ANALYSE_CSV": 0,
    "ANALYSING_CSV": 0,
    "VALIDATING_CSV": 0,
    "INSERTING_IN_DB": 0,
    "CONVERTING_TO_PARQUET": 0,
    "TO_ANALYSE_GEOJSON": 0,
    "ANALYSING_GEOJSON": 0,
    "CONVERTING_TO_PMTILES": 0,
    "CONVERTING_TO_GEOJSON": 0,
    "TO_ANALYSE_PARQUET": 0,
    "ANALYSING_PARQUET": 0
  },
  "cors": {
    "external_resources_with_cors_data": 42,
    "external_resources_without_cors_data": 55,
    "external_resources_cors_coverage_percentage": 43.3,
    "external_resources_allow_origin_distribution": [
      {
        "access_status": "Accessible (Specific Whitelist)",
        "unique_resources_count": 20,
        "percentage": 47.62
      },
      {
        "access_status": "Accessible (Wildcard *)",
        "unique_resources_count": 15,
        "percentage": 35.71
      },
      {
        "access_status": "Blocked (Missing Header)",
        "unique_resources_count": 5,
        "percentage": 11.9
      },
      {
        "access_status": "Blocked (Other Domain Only)",
        "unique_resources_count": 2,
        "percentage": 4.76
      }
    ]
  }
}

GET /api/status/crawler:

{
  "checks": {
    "in_progress_count": 5,
    "in_progress_percentage": 4.76,
    "needs_check_count": 60,
    "needs_check_percentage": 63.16,
    "up_to_date_check_count": 35,
    "up_to_date_check_percentage": 36.84
  },
  "resources": {
    "total_eligible_count": 95
  }
}

[maudetes]

Thank you for the refacto!