Add restock notifications

[cubefury]

This PR aims to adds a notification for when trades come off cooldown.

Closes: GTNewHorizons/GT-New-Horizons-Modpack#22906

Features:

• Reconnecting to a server will show restocked trades while you were offline.
• Plays a ding when notifying players of restocked trades
• Truncates displayed item list if there are more than 5 items in one notification, to prevent chat clutter.
• Robust to server restarts
• Notifications are muted when you're already accessing a vending machine
• Notifications can be disabled, and notification interval can be changed in configs, default enabled, checks every 10s.
• Clients connecting to servers will inherit the server's notification interval. Disabling notifications server-side disables it for all connected players.

Sample Notifications:

How it works:

• Server maintains a notification queue
• Purchasing item adds a notification to this pending queue, and enables a flag saved in the player's tradestate written to disk
• Every 10s a player entity exists, the server checks their queue for any trades off cooldown, sends the list to the client, and removes those trades from the notification queue
• Notifications are generated client-side from the received list
• If server restarts, trade state is read from disk to populate all players' notification queues

Tested in SP + MP daily 214

[chrombread]

a few quick syntax things

[cubefury]

ok I've also swapped a couple other instanceofs to the inline version, will do a more thorough pass on the other files later

[chrombread]

lgtm boss. code looks good logic wise but im not familiar with the vending machine codebase but test on server is always good 😎