Invocable approval helper

[Henk3000]

I wanted to use the flow action as shown on this article:
https://unofficialsf.com/use-flow-to-approve-reject-and-cancel-approval-processes/

As I now see in the comments the suggested code does not work, I investigated further and saw room for improvement.
I created 2 classes to be able to use the invocable approval actions
I removed the original flow example as it wasn't even calling the invocable action that was created in the article.

Other than that, it still works as described in the article

[alexed1]

Hi, Henk. This looks like a great improvement. What do you think of the idea of keeping the same name 'ResolveApprovalRequest'? We generally prefer to upgrade actions in place. It keeps things clearer.

[alexed1]

I realize now that Tamar also provide a pull request with fixes, at #1281.
I went ahead and merged her PR, but I'd still like to include your improvements if we can do it without changing the name of the action.

[alexed1]

Hi, checking back again. Let me know if you'd like to discuss this PR.