[`inputValueLookup(values, fieldName)`](https://github.com/blacktangent/react-layout-builder/tree/master/packages/react-form-utils#inputvaluelookupvalues-fieldname) currently, returning `null` value confuses the expected output for a lookup that searches a `fieldName` that does not exist in the values
inputValueLookup(values, fieldName)currently, returning
nullvalue confuses the expected output for a lookup that searches afieldNamethat does not exist in the values