This makes a few changes:
Make sure we always set `result.payload.isSponsored` and base it on
`SuggestProvider.isSuggestionSponsored()` so that it's really clear. With that
change, we don't need to set `suggestion.is_sponsored` anymore. (I'm trying to
stop modifying suggestion objects so much because it's hard to follow.)
Don't call `feature.makeResult()` if the feature is disabled. I'm kind of
surprised we don't do this already, but it's always worked out in the end due to
a few reasons: (1) Some `feature.makeResult()` implementations return null if
their prefs are disabled (effectively duplicating their `shouldEnable` logic),
(2) we don't query the Rust component for disabled suggestions, and (3)
`#canAddSuggestion()` returns null if sponsored/nonsponsored suggestions are
disabled.
Replace `#canAddSuggestion()` with `#canAddResult()`. The logic can be
simplified and is easier to follow if we always deal with results instead of
suggestions. Examples: (1) We can check `result.payload.isSponsored` instead of
having to also set and check `suggestion.is_sponsored`. (2) When checking for
blocked suggestions, we can check `result.payload.originalUrl` instead of
leaking `suggestion.rawUrl` from the Rust component.
Differential Revision: https://phabricator.services.mozilla.com/D235389
d7e7109d75