Add the 'respawn-at-bed' feature.

[CatTeaA]

Feature description

Add the 'respawn-at-bed' feature without bundling it with the 'respawn-at-home' option.

not the 'respawn-at-home-bed'

How the feature is useful

I hope that when players set up a bed, they will respawn next to the bed. If they have not set up a bed, they will respawn at the /spawn point, not at the /home point. It seems the current options do not allow for this.

The situation is that I started to restrict permissions related to /home a while ago, but some players had already set their /home points a long time before that. They are now respawning at the /home points they set, which is not what I want. The current options tie respawning at the bed with respawning at the /home point, and I can't seem to find a way to separate them.

If the 'respawn-at-bed' feature is added, I can maintain the ability for players to respawn next to their beds, and also prevent the issue where, if no bed is set, they respawn at the /home point instead of the /spawn point.

# When users die, should they respawn at their bed instead of the spawnpoint?

respawn-at-bed: true

PS: 'respawn-at-bed: true' seems to respect the vanilla behavior as well

I've also considered another solution, which is to add a feature like '/delhome player:*' to delete the /home points of all players on the server, but implementing it might be much more difficult. #5313