Add `Action` based `Match` (or similarly named) method

I am attempting to replace my custom T4 based union generator with dunet. Currently, my implementation generates an Either method which is functionally identical to the Match method generated by dunet, and a Do method, which is similar, but takes an Action for each union case, and does not return a value. Dunet does not appear to currently have such a method. The generated code should be identical to the current Match, except that it would return void rather than TMatchOutput, would take Action instead of Func delegates, and would not need to be generic on TMatchOutput, as there would be no output.

[TheJayMann]

Looking at the generated code, it appears that it would work well enough. I noticed that a corresponding task version is not created. Although this is not a feature I am seeking currently, I believe it would make sense to implement for the sake of symmetry.

[TheJayMann]

I’ve done similar in the past. For now, the way I decided to work around it is that I instead returned a different Action delegate for each match case, then invoked the action returned.

Anonymized example:

            union.Match<Action<Input>>(
                case1 => input => input.Value1 = case1.Value,
                case2 => input => input.Value2 = case2.Value,
                case3 => input => input.Value3 = case3.Value
            ).Invoke(input);