Check for incorrect metadata reading

[henrypinkard]

See micro-manager/pycro-manager#467

NDTiff v3.0 had a bug where in certain cases it would encode metadata in not i UTF-8 and maybe in UTF-16 or ISO-8859-1

fixed in v3.1

It might be a good addition to try to deserialize (in dataset.read_metadata()) with other encodings if it fails with JSON