Better display for rarely needed database fields.

[bernhardreiter]

Right now with fody 0.4.3 all unknown database fields will be displayed and can be edited as strings as well. This keeps fody flexible.

It is suboptimal for rarely used fields or fields that do not make sense for a CIDR contact.

One idea is to make some "extensible view" for these attributes, so they can be made visible if necessary but otherwise occupy only little screen space.