Support CallMethodAction with Custom Parameter

[michael-hawker]

It'd be nice for CallMethodAction to support an additional property for MethodParameter in order to allow overwriting the incoming parameter from the parent behavior to something specified by the developer in XAML:

  <b:CallMethodAction TargetObject="{x:Bind ContextFlyout}" MethodName="ShowAt" MethodParameter="{x:Bind FooElement}"/>

This would provide a little bit more flexibility.

[pedrolamas]

I can see the usefulness in what you ask... quite honestly, the whole code on the XamlBehaviors are still legacy from a time where we only had legacy Bindings (instead of compiled ones) and had to resort a lot to reflection, but nowadays that is not the case anymore... makes me wonder if a deeper rethink of this whole thing should be done for WinUI 3 support!