Omitting --add-to-reports and --searchable will unexpectedly set values

[cpliakas]

For example, if a field is added to default reports and you run field update without setting --add-to-reports, the field will be removed from the default reports. Omitting the option should not change the field setting.

[cpliakas]

Reopening, as c592fd0 is a half-fix. Need to introduce a breaking change to provide a sustainable fix.