Selector: Fix scoping logic of selector-native #5185

Description

As discussed in #5085 (comment), it would be worthwhile to try to fix the long-standing selector-native issue of not requiring all selector parts to match element under context, e.g. so that:

$div.find("div > *")

no longer matches children of $div.

My preliminary research indicates resolving this issue would cost about 1000 bytes minified gzipped; it'd still be 3300 bytes minified gzipped smaller than the full build compared to 4300 bytes minified gzipped without this change.

Link to test case

No test case since we don't upload selector-native versions anywhere. But the example from the description is pretty straightforward.