finish rewrite; port to cmake, loads of other changes

Theres documentation at https://sylvessa.zip/fourkit/ now. And a bunch of other changes. Check the discord server for a more comprehensive list

Minecraft.Server.FourKit/Event/Block/BlockExpEvent.cs

@@ -0,0 +1,31 @@
+namespace Minecraft.Server.FourKit.Event.Block;
+
+using Minecraft.Server.FourKit.Block;
+
+/// <summary>
+/// An event that is called when a block yields experience.
+/// </summary>
+public class BlockExpEvent : BlockEvent
+{
+    private int _exp;
+    internal BlockExpEvent(Block block, int exp)
+        : base(block)
+    {
+        _exp = exp;
+    }
+
+    /// <summary>
+    /// Get the experience dropped by the block after the event has processed.
+    /// </summary>
+    /// <returns>The experience to drop.</returns>
+    public int getExpToDrop() => _exp;
+
+    /// <summary>
+    /// Set the amount of experience dropped by the block after the event has processed.
+    /// </summary>
+    /// <param name="exp">1 or higher to drop experience, else nothing will drop.</param>
+    public void setExpToDrop(int exp)
+    {
+        _exp = exp;
+    }
+}