Target type of generic version of MvxTargetBinding<TTarget, TValue> is incorrect
### Discussed in https://github.com/MvvmCross/MvvmCross/discussions/4385

<div type='discussions-op-text'>

<sup>Originally posted by **ivmazurenko** March  3, 2022</sup>
https://github.com/MvvmCross/MvvmCross/blob/1c002b3ba5148e10822ddaaade1a0a5b9fb0adfa/MvvmCross/Binding/Bindings/Target/MvxTargetBinding.cs#L70

Please, take a look for this line. Maybe i am wrong, but this property is used only once, when default value will be created in `MvxFullBinding`:

https://github.com/MvvmCross/MvvmCross/blob/1c002b3ba5148e10822ddaaade1a0a5b9fb0adfa/MvvmCross/Binding/Bindings/MvxFullBinding.cs#L170

Thus, I think, this line should be:
``
public Type TargetType => typeof(TValue);
``

Because it is type of value that will be applyed for target.

Can anybody explain me, why it is done this way? </div>