Add Sentinel-3 SYNERGY and LST

[konstntokas]

• Switched spatial resampling to the new xcube_resampling library, replacing the
  deprecated xcube.core.resampling module.
• Added support for Sentinel-3 SYNERGY Level-2 NTC (sentinel-3-syn-2-syn-ntc)
  via the Copernicus Data Space Ecosystem (CDSE) STAC API.
• Added support for Sentinel-3 SLSTR Level-2 Land Surface Temperature NTC
  (sentinel-3-sl-2-lst-ntc) via the CDSE STAC API.
• Added support for Sentinel-3 SYNERGY Level-2 NetCDF
  (sentinel-3-synergy-syn-l2-netcdf) via the Microsoft Planetary Computer STAC API.
• Added support for Sentinel-3 SLSTR Level-2 Land Surface Temperature NetCDF
  (sentinel-3-slstr-lst-l2-netcdf) via the Microsoft Planetary Computer STAC API.
• Fixed an issue in stac-cdse-ardc and stac-pc-ardc when generating ARDC from
  Sentinel-2 Level-2A (sentinel-2-l2a) products; mosaicking of integer arrays
  now works correctly when requesting the Scene Classification Layer (SCL).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.15%. Comparing base (2847ffb) to head (ce63e80).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #47      +/-   ##
==========================================
+ Coverage   93.97%   98.15%   +4.18%     
==========================================
  Files          13       13              
  Lines        1461     1467       +6     
==========================================
+ Hits         1373     1440      +67     
+ Misses         88       27      -61     

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