[CLA] Avoid iOS body scroll reset in dojo/window.scrollIntoView, fixes #17740

This PR updates `dojo/window.scrollIntoView` to scroll the body in a way that avoids an iOS issue with resetting `body.scrollLeft` when `body.scrollTop` is set and vice versa.

I looked at adding a unit test for this, but the dojo/window tests are already failing on iOS, and I don't have time to address them. However, I hope to update them as part of the doh-to-intern conversion. Maybe something can be done then.

I ran the dojo package's test suite in the following environments to verify that this fix did not cause test failures (or additional failures in environments already experiencing failures on dojo `master`):
* Win7 + IE8,9,10 
* Win7 + Chrome latest
* Win7 + FF latest and latest FF ESR
* Win8 + IE11
* OSX + Safari 6.1
* OSX + Chrome latest
* OSX + Firefox latest
* Arch Linux + Chromium latest
* Arch Linux + Firefox latest