Do not allow insert if the namespace is incorrect

[mortenwh]

Currently, it is possible to add datasets with namespaces "no.met.dev" and "no.met.staging" in the production env. This should not be allowed. We need to update dmci to only insert datasets with complies with namespaces defined in the config file. So;

• Prod should only accept no.met
• Staging should only accept no.met.staging and no.met
• Dev should only accept no.met.dev and no.met