Fix import of default values from xls

The default values are specified on the `repositoryroot`. But this type doesn't have a lot of field used on `repositoryfolder`. This means that default values which don't have a corresponding field on the `repositoryroot` are dropped and not inherited.

This fix sets the default values directly on the top-level `repositoryfolder`. This allows all nested elements to inherit or override those values.

@phgross