fix #675 Dialog disappears after resize

When the viewport was resized significantly, so that dialogOldPosition.left
> newViewport.width, the Dialog disappeared and never appeared again.

The problem was introduced in e6405a1b79c707f2b4090875ea2e2673f29d5c71 by
the check if refence position is in viewport before displaying the popup.

However it seems that this check is redundant and only introduces
problems. What this commit does is just removing that `if` (the rest is
formatting).

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The issue is coming from the CR "error tooltip enhahcement", I've checked on the demo page and the feature is working fine without the check that I'm removing; also no tests are failing, so I hope this fix should be fine.