Improve `hide-if-labelled-by` snippet

Background

The hide-if-labelled-by currently suffers when junk layout is part of the content.

There are cases where the targeted node with aria-labelledby is actually not readable, visible, or select-able, and in such case we should not look for its container, as it's not relevant for the user, or the screen reader.

What to change

Guard related labels to be part of meaningful content.