Same-site debouncing restriction should be based on eTLD+1

[pilgrim-brave]

Currently we don't debounce a link if two hops in the chain have the same origin. This should be expanded to be eTLD+1 matches, not just origin.

For example, currently this chain is not debounced in Brave:

from.example -> a.click.example/bounce -> a.click.example/dest

bc /bounce and /dest share the origin.

However, this chain would be debounced:

from.example -> a.click.example/bounce -> b.click.example/dest

The correct behavior is for neither of the above redirect chains to be debounced

[kjozwiak]

Labelled as QA/No after discussing the above with @pes10k and @pilgrim-brave via the Slack thread that @LaurenWags started.