Allow option to $expand on PUT/POST/PATCH about angular-odata-es5

[jonest]

I'm happy to work on adding this, but I'd like to hear some thoughts/get some guidance on how best to tackle this :)

[jonest]

I started taking a peek through the code to configure this similar to the Get( ... ) operation that currently exists and saw that there are PostOperation<T>, PutOperation<T>, and PatchOperation<T> that have been commented out with a comment //ToDo: Check ODataV4. I'm not entirely sure what problem exists where this was left like this.

Would you mind elaborating at all on this @StefH ?

Thanks!

[StefH]

Actually I don't know the full details on this code part. I think I copied this from the older project.
And I never got the chance to analyze and implement this functions.

If you have time, you can add this (if possible including unit-tests)