Petascope - display non-ascii string in coverage's metadata

[Bang Pham Huu]

For example, if in the ingredients file of wcst_import, it has this non-ascii character µ.

"metadata": {
                    "type": "xml",
                    "global": {
                        "Title": "'This is a test coverage 1'",
                         "test": {
                            "Band_1": {
                                "name": "coastal aerosol",
                                "central Wavelength": "0.443 µm"
                                   }
                           }
                    }
                }

Then, petascope should save it and can display it as it is with the output of DescribeCoverage request.