Add PlayerTeleportFailedEvent

Is your feature request related to a problem?

Hello 👋🏻 currently there is no way to know if a teleport failed due to a player having passengers. Which means if any plugin uses player.teleport() the teleport fails. This is a huge problem as it prevents compatibility between plugins.

Describe the solution you'd like.

I would like to see a PlayerTeleportFailedEvent added to paper. This means that when a teleport fails we could handle the passengers correctly and then re-teleport the player to enable the functionality again.

Describe alternatives you've considered.

I have tried the PlayerCommandPreprocessEvent to listen in on commands that teleport the player although this is limited as it means every single command needs to be manually added and there is no way to detect plugins that use teleporting it in other cases.

Other

I did find that there was a pull request for this exact feature #10173 and even though it had a lot of engagement it was never added 😟

Start by reviewing pull request #10173 and the existing player.teleport() behavior; PlayerCommandPreprocessEvent is only the stated workaround. Done means Paper exposes PlayerTeleportFailedEvent when a player teleport fails because of passengers, allowing plugins to handle the passengers and retry the teleport.