* $(node).prop(foo) -> node.foo
* For objects only expected to represent a single element,
use native querySelector() and its natural null return
fallback, instead of `$(), $.length, $()` etc.
* Fix a few minor non-voting eslint warnings that were in the CI
output about line length and unknown type "bool".
* Remove presumed outdated comment about Vector splitting,
per T234907.
* Rename ulsPosition to configPosition to be more clearly
different from ulsPopupPosition.
* Remove various 'uls' prefixes of local variables,
since this is ULS code in the ULS repository.
Change-Id: I1c617bf48283f47dc948550111c515faf173d1eb
977e6c68c2