Fix Dialog command

[Dueris]

The /dialog command is disabled in Folia, which this PR fixes. The command itself is relatively simple, and the entire dialog system is run on just packets(at least for the server side). The dialog system is only disabled, in Folia, from the command side. Plugins and signs can still execute dialog operations on Folia.

The dialog command only iterates over the target players, and sends a packet. The changes in this PR basically just schedule the sending of the packets to the target player scheduler, which while simple, fixes the dialog command functionality.

For testing purposes, I used the example dialog commands from the Minecraft Wiki:

/dialog show @a minecraft:server_links
/dialog show @a {type:"minecraft:notice",title:"Hello"}
/dialog show @a {type:"minecraft:confirmation",title:"Give yourself diamond?",yes:{label:"Yes please","action":{"type":"run_command","command":"give @s diamond"}},no:{label:"Nope"}}
/dialog clear @a