Append record stub & union pattern match case

This PR contains the previous one (#480) and contains union pattern match case appending instead of prepending.

* [ ] Fix issue with when multiple record fields are on the same line
* [ ] Enhance code gen when multiple pattern match clauses are on the same line
* [ ] Add optimization similar to (https://github.com/fsprojects/VisualFSharpPowerTools/commit/2a496b259ab2cb70551b6e86d5acfe69acdacbf1)
* [ ] see if we can improve the check
That is more elegant I think.