Add Player Chat Completion Suggestions

[NotSoDelayed]

Description

This PR adds player's chat completion suggestions support to Skript! Javadocs:

• https://jd.papermc.io/paper/1.20/org/bukkit/entity/Player.html#addCustomChatCompletions(java.util.Collection)
• https://jd.papermc.io/paper/1.20/org/bukkit/entity/Player.html#removeCustomChatCompletions(java.util.Collection)
• https://jd.papermc.io/paper/1.20/org/bukkit/entity/Player.html#setCustomChatCompletions(java.util.Collection)

---

Target Minecraft Versions: Minecraft 1.19+ Requirements: Spigot 1.19+ Related Issues: none

[AyhamAl-Ali]

@DelayedGaming 👋