data.RecordFactory: field calculate & convert not reflecting updates

@Dinkh @maxrahder

in general we should discuss if we really need both: calculate and convert. i personally think that just one of them is sufficient, since both are based on functions (e.g. fat arrows).

the important point about this ticket: if we generate a new field like

{
    name: 'fullname',
    convert: data => `${data.firstname} ${data.lastname}`
}

the field needs to update in case any of the used fields inside the convert / calculate fn body get changed at run time. this is very similar to the way model.Component based bindings work.