Mapscript provider configuration parser not use storage_crs as defined in the documentation

[PhilippePinheiroLIST]

Description
Mapscript provider not use storage_crs as defined in the documentation but expect a number representing the ESPG in options.projection
So maps based on data not using EPSG:4326 projection are not working if we respect the documentation syntax

Steps to Reproduce
Configure an OGC API Maps Collection based on a geoTIFF or Shapefile having a projection other than EPSG:4326

Expected behavior
Generated Mapfile layer shoud use the storage_crs projection, currently it always use EPSG:4326, so genrated images are often empty due to bad data reprojection

Screenshots/Tracebacks

Environment

• OS: Ubuntu 24.04.4 LTS (Noble Numbat)
• Python version: 3.12.3
• pygeoapi version: 0.24

Additional context
based on Mapscript documentation, we should use storage_crs to define the data projection :

providers:
          - type: map
            name: MapScript
            data: /maps/PARCELLES.shp
            options:
              type: MS_LAYER_POLYGON
              layer: PARCELLES
              style: /maps/PARCELLES.sld
            format:
              name: png
              mimetype: image/png
            storage_crs: http://www.opengis.net/def/crs/EPSG/0/2169

But then the generated mapfile layer uses :

    PROJECTION
      "proj=longlat"
      "datum=WGS84"
      "no_defs"
    END # PROJECTION

one bypass solution is to use the "options.projection" parameter :

providers:
          - type: map
            name: MapScript
            data: /maps/PARCELLES.shp
            options:
              type: MS_LAYER_POLYGON
              layer: PARCELLES
              style: /maps/PARCELLES.sld
              projection: 2169
            format:
              name: png                                                                                                         
              mimetype: image/png

then the generated mapfile layer projection is EPSG:2169

Based on the following code snippet inside "pygeoapi/provider/mapscript_.py"

            try:
                self.crs = int(self.options['projection'])
            except KeyError:
                self.crs = 4326

            self._layer.setProjection(self._epsg2projstring(self.crs))

I think there are 2 solutions :

• adapting the Mapscript documentation so we know that we have to define the "options.projection" parameter
• changing the code so it stops using option.projection and uses the CRS defined by storage_crs