[B] Added TeleportCause for /tp <x> <y> <z>. Fixes BUKKIT-5348.

## The Issue:
Currently, when teleporting with /tp x y z, the TeleportCause is not set, e.g. the default value is used instead of the expected TeleportCause.COMMAND. With the /tp player1 player2 syntax, the TeleportCause is already correctly set to TeleportCause.COMMAND.

## Justification for this PR:
With the Issue described above, plugins cannot for example filter out teleports caused by the /tp command correctly and react to them.

## PR Breakdown:
Adds the correct TeleportCause to the call of the Player.teleport method.

## JIRA Ticket:
BUKKIT-5348- https://bukkit.atlassian.net/browse/BUKKIT-5348