Allow Descriptive LineItem Without UnitAmount and Quantity

[arahmancsd]

SDK you're using (please complete the following information):

• Version [e.g. 0.1.0]

Xero.Api.SDK.Core 1.1.4

Is your feature request related to a problem? Please describe.

Currently, a LineItem object in the invoice doesn't allow a descriptive line. Every LineItem object must have UnitAmount and Quantity. However, we need a descriptive line in the invoice without those fields as in the below picture.

Describe the solution you'd like Allow descriptive LineItem without UnitAmount and Quantity fields. The UnitAmount & Quantity are both nullable, however, it doesn't allow creating an invoice without them.

Below are the two fields from the LineItem documentation, Both are nullable and don't emit default values as well. So the implementation shouldn't bring huge changes in the invoices.

        //
        // Summary:
        //     LineItem Quantity
        //
        // Value:
        //     LineItem Quantity
        [DataMember(Name = "Quantity", EmitDefaultValue = false)]
        public decimal? Quantity { get; set; }

        //
        // Summary:
        //     LineItem Unit Amount
        //
        // Value:
        //     LineItem Unit Amount
        [DataMember(Name = "UnitAmount", EmitDefaultValue = false)]
        public decimal? UnitAmount { get; set; }

[itsisaf]

Any update on this?