[Lua] Castle Zvahl Teleporters

[dallano]

I affirm:

• I understand that if I do not agree to the following points by completing the checkboxes my PR will be ignored.
• I understand I should leave resolving conversations to the LandSandBoat team so that reviewers won't miss what was said.
• 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?

• Adds retail accurate functionality to the telepads in Castle Zvahl Keep
• Achieved by running each telepad on an individual timer between 20-50 seconds as witnessed in linked capture. A table was created that ties each npc ID with the appropriate event ID and trigger area. Whenever that portal is opened on its cooldown, the appropriate trigger area checks if said portal is open to allow the player to travel through.
• Implemented an auto-teleport feature that is also evident in retail: The player is automatically teleported if already standing on the telepad. This is achieved by setting a variable on the player. When a portal is triggered it searches for players with the appropriate variable set. If such a player is discovered, the appropriate event is called to teleport them automatically. This variable is unset when player leaves trigger zone.

Captures: https://1drv.ms/f/s!AtUZibtOtozEhoBMroc6yCCkVgliXg?e=bhhaKF

Steps to test these changes

Walk into a portal if it appears open, and be teleported to the appropriate location
Walk into a portal if it appears closed
Stand in closed portal and wait for it to open and be teleported without having to re-enter the platform