Cast all values in string fields to strings. Rehydrate as strings too.

[straleyb]

Currently there are many fields that save uris as uris and it shouldnt. It should also rehydrate them as strings even if they are URIs in git.

[lsat12357]

which fields are the string fields?

[lsat12357]

So at the moment we are treating only the fields with language properties as strings: title, publisher, label, alternateName, comment No fields should accept both uris and strings