Unclear error message when CRS is missing #47
Description
When I first tried to import a file, I got this error:
cjdb.modules.exceptions.InvalidMetadataException: The file should contain a member'metadata', in the first object
I was first confused because according to CityJSON specifications it is not mandatory in a CityJSON file to have a "metadata" object. I then added an empty metadata object and got another error which made everything clearer:
cjdb.modules.exceptions.MissingCRSException: No Coordinate Reference System specified for the dataset. Use -I/--srid flag to define the SRID.
With this second message it's clearer, so it could be good to update the first message with a mention to CRS.