/spawn command configuration

CMDBOOK-2295 - Reported by Amicus.Minecraft

Can the /spawn command be configured to send a player to one spawn point regardless of which world they are in?

Say I have the following worlds:
# WORLD
# WORLD_NETHER
# CREATIVE
# GASBOMBS

If a player uses /spawn in GASBOMBS, I want them to be teleported to the spawn point of WORLD, *not* the spawn point of GASBOMBS.

In the configuration file, this option could have two settings.

$ spawn-locations:
$ exact-spawn: false
$ main-world: WORLD
$ multiworld-spawn: false

Set "multiworld-spawn" to "true" to enable the current system of each world having its own spawn. Set it to "false" to have all '/spawn' command executions send the player to the main world's spawn.

该 issue 未指出任何文件或测试。首先定位 /spawn 命令及其配置处理逻辑，然后跟踪特定于世界的 spawn 选择是如何工作的。完成的标准是：配置可以在每次执行 /spawn 时选择对应世界的 spawn 或主世界的 spawn，并且两种设置都有测试覆盖。

由索引模型根据 Issue 内容生成。