Is there an existing issue for this?

• I have searched the existing issues

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

With a ContainerResource, after the object is constructed, you can mutate the image via WithImage() extension methods.

There is no equivalent for the command or working directory on ExecutableResources - once the object is constructed, you can't change the value (at least not without reflection!).

Describe the solution you'd like

The Command & Working Directory should be moved from properties on ExecutableResource to annotations, and WithXYZ() extension methods to mutate them after the fact.

Additional context

This work is likely required for #8984