Improve connected overlay positioning

[nestorrente]

When using appendTo="body", dropdown's option list overflows the viewport's width if the element is near to the right side of the screen, even if there is enough space to display the list:

You can see it in action here: https://codesandbox.io/s/hardcore-satoshi-xz465?file=/src/components/HelloWorld.vue

I think the problem is at this line of DomHandler:

primevue/src/components/utils/DomHandler.js

Line 199 in d624e17

if (targetOffset.left + targetOuterWidth + elementOuterWidth > viewport.width)

The current condition is:
targetOffset.left + targetOuterWidth + elementOuterWidth > viewport.width

which I think is not right, because it is adding both the target and the element width. I think the right condition would be:
targetOffset.left + elementOuterWidth > viewport.width

With this change, the result is:

Do you see any issues with doing that change?

[cagataycivici]

I've ported the algorithm we use in PrimeNG which is more mature and proven to be more precise.