Include Sticky Sea Instance to Instance quests

Suggestions
1

Imported from legacy Flarum.
Original author: aewuu (Flarum #575)

Suggestion: Sticky Sea is an instance. It should be in the instance quests for rewards.

2

Imported from legacy Flarum.
Original author: KaptainPickles (Flarum #722)

+1 please please. Also needs to be added to @cooldowns