wcst_import - supports metadata option for old recipes

[Bang Pham Huu]

Currently, old recipes (map_mosaic, regular_time_series, irregular_time_series) don't support feature to fetch metadata from files (global and local).

This should be supported in these old recipes as same as general_recipe with slicer gdal, e.g:

            "global": {
              "Title": "'Drought code'"
         	  },
             "local": {
                  "local_metadata_key": "${gdal:metadata:local_metadata_key}",
                  "metadata_file": {
                       "root_element": "INSPIRE",
                       "path": "replace('${file:path}', '.tiff', '.xml')"
                  }
              }
          },