Gets or sets the process result produced by the invocation.
public ProcessResult? Result { get; set; }
Owned by the pipeline, not by caller code. Only the CliInvoke.Core.Middleware.MiddlewareChain
walker, the terminal delegate, and propagating middleware may set this. Reading it
before the chain completes returns null. Derived contexts (created
via WithConfiguration(ProcessConfiguration)) share the same result state.