refactor(position): Remove deprecated body scrollTop and scrollLeft

Removes the use of deprecated variables in strict mode which caused the following errors(#1658).
```console
body.scrollTop is deprecated in strict mode. Please use 'documentElement.scrollTop' if in strict mode and 'body.scrollTop' only if in quirks mode.
body.scrollLeft is deprecated in strict mode. Please use 'documentElement.scrollLeft' if in strict mode and 'body.scrollLeft' only if in quirks mode.
```