Fix some issues in set_entity_pose()

* Fix exception when setting poses on Spigot
* Fix being able to set poses for Mannequins on Spigot
* Fix exception when Mannequins are set to now invalid poses
* Add 'fixed' argument for function on Paper servers

Author: PseudoKnight

src/main/java/com/laytonsmith/abstraction/MCEntity.java

@@ -126,6 +126,6 @@ public interface MCEntity extends MCMetadatable {
 
 	MCPose getPose();
 
-	void setPose(MCPose pose);
+	void setPose(MCPose pose, boolean fixed);
 
 }

src/main/java/com/laytonsmith/abstraction/bukkit/entities/BukkitMCEntity.java

@@ -446,7 +446,11 @@ public MCPose getPose() {
 	}
 
 	@Override
-	public void setPose(MCPose pose) {
-		e.setPose(BukkitMCPose.getConvertor().getConcreteEnum(pose));
+	public void setPose(MCPose pose, boolean fixed) {
+		try {
+			e.setPose(BukkitMCPose.getConvertor().getConcreteEnum(pose), fixed);
+		} catch (NoSuchMethodError ex) {
+			// either Spigot or prior to 1.20.1
+		}
 	}
 }

src/main/java/com/laytonsmith/abstraction/bukkit/entities/BukkitMCMannequin.java

@@ -1,6 +1,8 @@
 package com.laytonsmith.abstraction.bukkit.entities;
 
 import com.laytonsmith.abstraction.entities.MCMannequin;
+import com.laytonsmith.abstraction.enums.MCPose;
+import com.laytonsmith.abstraction.enums.bukkit.BukkitMCPose;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Mannequin;
 
@@ -27,4 +29,9 @@ public boolean isImmovable() {
 	public void setImmovable(boolean immovable) {
 		this.m.setImmovable(immovable);
 	}
+
+	@Override
+	public void setPose(MCPose pose, boolean fixed) {
+		this.m.setPose(BukkitMCPose.getConvertor().getConcreteEnum(pose));
+	}
 }

src/main/java/com/laytonsmith/core/functions/EntityManagement.java

@@ -5831,6 +5831,9 @@ public String docs() {
 					! Goat
 					| LONG_JUMPING
 					|-
+					! Mannequin
+					| Only FALL_FLYING, SLEEPING, SNEAKING, STANDING, SWIMMING
+					|-
 					! Player
 					| SPIN_ATTACK
 					|-
@@ -5861,12 +5864,20 @@ public String getName() {
 			return "set_entity_pose";
 		}
 
+		@Override
+		public Integer[] numArgs() {
+			return new Integer[]{2, 3};
+		}
+
 		@Override
 		public String docs() {
 			return """
-					void {entityUUID, pose} Sets an entity's pose. While you can set any pose to any entity, only
-					certain poses will result in a visual change for a particular entity type. Poses can affect entity
-					hitboxes but do not change entity state. See {{function|get_entity_pose}} for a list of poses.
+					void {entityUUID, pose, [fixed]} Sets an entity's pose. (only Mannequins on Spigot)
+					The fixed argument is a boolean for whether the pose should stay unless manually changed.
+					(defaults to false) While in most cases you can set any pose to any entity,
+					only certain poses will result in a noticable change for a particular entity type.
+					Poses can affect entity hitboxes but do not otherwise change entity state.
+					See {{function|get_entity_pose}} for a list of poses.
 					""";
 		}
 
@@ -5876,10 +5887,14 @@ public Mixed exec(Target t, Environment env, Mixed... args) throws ConfigRuntime
 			MCPose pose;
 			try {
 				pose = MCPose.valueOf(args[1].val().toUpperCase());
+				boolean fixed = false;
+				if(args.length == 3) {
+					fixed = ArgumentValidation.getBooleanObject(args[2], t);
+				}
+				entity.setPose(pose, fixed);
 			} catch(IllegalArgumentException ex) {
-				throw new CREFormatException("Invalid pose: " + args[1].val(), t);
+				throw new CREFormatException("Invalid pose for this entity: " + args[1].val(), t);
 			}
-			entity.setPose(pose);
 			return CVoid.VOID;
 		}