Fix QUEST_CONTENT_LEAVE_SCENE

[scooterboo]

Description

There was no trigger for QUEST_CONTENT_LEAVE_SCENE, and the logic behind checking it needed to be brought in line with most of the other quest content logic.

Issues fixed by this PR

On the very last part of clan head dude's story quest, he tells you to GTFO of his mansion, but the quest wasn't finishing.

Type of changes

• [x] Bug fix
• [x] New feature
• [x] Enhancement
• [ ] Documentation

Checklist:

• [x] My code follows the style guidelines of this project
• [x] My pull request is unique and no other pull requests have been opened for these changes
• [x] I have read the Contributing note and Code of conduct
• [x] I am responsible for any copyright issues with my code if it occurs in the future.