FIX - rasql check the number of dimensions in the encoding

[Bang Pham Huu]

For example, encoding a 3D collection in 2D has this error message:

  <ows:Exception exceptionCode="RasdamanRequestFailed">
        <ows:ExceptionText>Execution error 381 in line 1, column 8, near token encode: Error in convertor of the selected data exchange format.</ows:ExceptionText>
    </ows:Exception>
    <ows:Exception exceptionCode="RasdamanRequestFailed">
        <ows:ExceptionText>Failed internal rasql query: SELECT encode(c, "image/tiff" , "{\"geoReference\":{\"crs\":\"EPSG:4326\",\"bbox\":{\"xmin\":-63.151668548583984,\"ymin\":-35.91914992988281,\"xmax\":-62.415750948583984,\"ymax\":-35.02583312988281}},\"metadata\":{\"Title\":\"This is the test coverage\"},\"nodata\":[-0.999]}")   FROM single AS c </ows:ExceptionText>

It'd be much better to check for some well-known encoding format, if 3D is not supported beforehand with better error message:

Format conversion failed: Format conversion failed: cannot encode 3D array with the GDAL library, only 2D is supported