GetObjectLookup<T>: misleading parameter order — replace with GetLookupField<T>

[Giannoudis]

Problem

GetObjectLookup<T> has the following signature:

public T GetObjectLookup<T>(string lookupName, string objectKey, string lookupKey = null, string culture = null)

The parameter order is inconsistent with GetLookup<T>(lookupName, lookupKey, culture).
Callers naturally pass the lookup key as the second argument, which silently lands in
objectKey instead — leaving lookupKey = null and causing a runtime ArgumentException.

Resolution

• Remove GetObjectLookup<T>
• Add GetLookupField<T> with corrected, unambiguous signature:

public T GetLookupField<T>(string lookupName, string lookupKey, string fieldName, string culture = null)

Usage

// Full object deserialization — unchanged
var param = GetLookup<SZWParam>("SZWParameter", "2026");

// Single field extraction — new
var rate = GetLookupField<decimal>("SZWParameter", "2026", "AwfLaag");

Affected file

PayrollEngine.Client.Scripting/Client.Scripting/Function/PayrollFunction.cs