[lua,sql] Implements Pernicious Presents treant event

[CriticalXI]

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• I have read and understood the Contributing Guide and the Code of Conduct.
• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

• Recreates the 2003 event Pernicious Presents, which spawns treants throughout the world that block outpost teleport usage.
• Creates a command to interact with the event !treants.

Steps to test these changes

• Use !treants start to manually trigger the start of the event.
• See outpost NPCs are made invisible
• See game wide announcements when the treants are defeated