Feature: consider a way to indicate what fields are sensitive

### Feature description

The platform team has submitted this feature request. It was initially created as part of another issue: https://github.com/ConduitIO/conduit/issues/1558.

Clients require the ability to determine which situations require obfuscating their values. My recommendation is to derive this from the data type rather than manually indicating whether the information is sensitive. This issue should track progress on this approach.